Diagnosis and Repair of Problems With Your Imperial's Fuel Pump


Imperial Homepage -> Repair -> Fuel -> Pump

Tip from John (1981-1983):

This fuel pump can give you problems when it is not really broken. Disconnect the battery first. Isolate the leads to the pump. Disconnect them and reverse the pump. What happens is it ingests some of the plastic from the now deteriorating plastic intake screen and jambs. What you can also do is remove trunk floor carpet, carefully cut access hole (very difficult but worth it, remove pump and pickup, clean out crap, replace screen or just add a pickup extension made of fuel hose. The pump is really heavy duty engineering and should not wear out in your lifetime.

Addition from Dick:

Rather than cut a hole in the floor, it is very easy to remove the whole tank and get at the fuel pump that way. Of course you need to drain the gas first. The fuel pumps that I have had fail on me (two of them) both failed in the same way, namely the outer case cracked, so that when the pump runs, it sprays fuel all over the inside of the tank, and none goes into the outlet line. When this happens, you must replace the pump.

Tip from Kerry:

I've changed quite a few fuel pumps on various mopars but the last two have taught me something. I could NOT get my 300 to pick up fuel. I
had the pump off a half dozen times before I decided it just wasn't getting any stroke from the pushrod. Removing the allen plug, I dropped
the pushrod and looked it over. It's made to have a small turned area on each end and I noticed the turned end looked shorter on one end than
the other. Since I have a couple 413's in the corner, I pulled the rod from one and to my surprise it was about 1/4 inch longer and showed no signs of the wear that the one that came out of the 383 did. When I put the 'new' pushrod in the 383, she fired right up and starts instantly.

This past weekend, Jay King called me broken down in Huntsville. Car just died and we suspected the fuel pump. New pumps were relatively
easy to get and although we didn't have all the correct tools, I had it swapped out in an hour or so. Cranked it over and no gas... Hummm

Out came the allen plug and the pushrod and sure enough it was about 1/4" short on one end. Of course the pushrod is not a stock item but it came it yesterday and as soon as I installed it the car fired right up.

I'm assuming this is a wear item that is supposed to wear before the cam lobe does.

The moral of this story is that in the future when I run into what feels like fuel delivery issues, I'll probably suspect the pushrod before I assume it was the fuel pump.

Btw, Advance can get them overnight for about 18 bucks.


I'm planning to install electrical fuel pumps on a couple of my cars (in-line with the existing mechanical pumps). The OEM Carter mechanical pumps are rated at 3.5 to 5 psi (15 gph minimum @ 500 rpm). I'm looking at a couple of Borg-Warner electrics, one for "Import Vehicles" rated at 4.0 to 5.5 psi (22 to 38 gph) and another labeled "Domestic Vehicles" rated at 6.5 to 8.0 psi (26 to 32 gph). The B-W units are identical except for the pressure ratings. Any thoughts on which pump to use?


From Kne:

I would think that for a normal car you would want the lower pressure pump, as around 5psi is normal. On the cars I bracket race, I use 8 psi pumps, but use a regulator and set them at 7psi. They have a hi-po 4bbl 360 and hi-po 4bbl 440, both are capable of about 13.5 in the quarter mile, but usually run at 14 flat since I don't have slicks. I can't imagine running a high pressure pump with a 2bbl carb. I believe that at over 7 psi you can start getting problems with the floats not being able to shut off the needle valves, and start getting too much gas. Of course the really all out racers/fire breathing engines will use way-higher pressures, but regulate them down quite a bit as the float and needle valve can only overcome so much. So.....I would suggest a regulator if you use the 6.5-8.0 psi pump, although you could most likely run it without problems without a regulator, but may get some flooding or extra fuel consumption, with no additional gain over the lower pressure pump. Also, like oil, volume is more important than pressure, so make sure you don't have any funky bent and kinked fuel lines.

From Dick:

You had better avoid anything over about 5 PSI, too much pressure can override the float level setting and make your car run too rich, maybe much too rich. If you think you need the higher GPH capacity, you should install a fuel pressure regulator at the carburetor to prevent anything over 5 PSI. As far as GPH, Even if you are escaping from a bank holdup in Sacramento and running up I-80 toward Truckee, you would only need 8 GPH, figuring 10 mpg and 80 MPH! (You don't want to attract the CHP, do you?)

From George:

Yea, in my childhood it was thought that a bigger carb+MORE gas= greater SPEED...until a buddy put a huge Holley and a electric pump on a stock 283 Nova. All he got was Chevy Flambe'!

Question from Bob:

We are working on the fuel system on the Imperial. There is a small clear tubing that connects the incoming (from tank) to the outflow ( to fuel filter). We bought a new fuel pump but it doesn't have the right fitting to allow us to reconnect this. We have checked everywhere for an adapter (1/4 to 1/8 - different thread patterns) and have had no luck. Does anybody know what this line is for?


From Roy:

Whatever it is, it is not original, the OEM fuel pump is connected to the metal fuel line from the tank with a piece of hose and the pump outlet has a threaded fitting with a short metal line to the fuel filter which in turn is also connected with a short piece of hose. What you describe might have been some sort of bypass for an electric fuel pump located elsewhere. It is counter productive to the mechanical pump, preventing it from building up any pressure, since the fuel simply flows through the tube back past the pump! Without that tube your old fuel pump may have been satisfactory.

From Ron:

If it's the line I'm thinking about, it was used as an attempt to prevent the peculating of fuel in the float chamber/ intake manifold when the engine was turned off. When you turn off the engine, fuel pressure is still there in the lines. The 1/8th inch line was to relieve that pressure by allowing the excess fuel to bleed back to the fuel tank. Many of those fittings were thrown away at the dealerships because of the complaints of excessive cranking when you went to restart the engine

Question from Mindy (1953):

I'm in need of a fuel pump for my '53. It has a 331 in it so it has an extra long "arm" on it.   Does anybody knows where I can have mine rebuilt or where I can find a kit for it?


From Dan:

Call EGGE's 1-800-866-3443 Cat# 1027 page 27 line 37 part# M8405

From Mark:

I have a 54 New Yorker with the 331 engine in it. Unless there is a major difference between a 53 and a 54, a late model (60's) 318 fuel pump should work. That's what I have on mine. Has worked great for 10 years. It won't be original looking, but it will do the job.

From Dick:

If you have the old pump, it can be rebuilt by any of the chain auto parts stores. It will take a few weeks, but they will do it right. I recommend you take it to your local NAPA store.

Question from Currell (1953):

Here's the situation: My '53 Imperial, largely original with under 70K miles, sat in my garage from 1990 through 2002, run only twice, on consecutive days in '97, after a lot of work on my part. I recently had some work done on it by a master Chrysler restorer, including getting the motor running again. And it ran, after about a half hour of roughness at the shop, smoothly and quietly. The carb is newly rebuilt, by the way. But here's the problem: Driving it home in September in low 90 degree weather, it "vapor locked" after about 10 miles of driving, and 6 more times until I got it home, which was about a 20 mile trip. Each time, I would pull it off the road, let it sit for about 5 minutes, and it would easily start again, no sweat. Then, about 1.5 miles lately, just like clockwork, it would do it again. And over and over. I'd step on the gas, it would stumble, and then...nothing. This was scary, being in metro Detroit traffic. I even bought 2 pounds of ice at one stop, and packed it around the fuel pump, but I can't say that it helped. The power steering goes too, of course...This beat a workout at the gym, since I am more of the distance runner build (20 marathons) than weightlifter! I was lucky to get it back home. A couple of weeks later, with the temps in the 70s, I drove it again. It went about 10 miles or so, maybe a bit longer, and it stopped again. This time I was pretty close to home, so I got it back OK. Started readily after the usual 5 minute wait. A third time, it was in the 50s or something. I only drove it less than 10 miles, and no stalls. Is this definitely a fuel pump problem? If yes, is a rebuilt one to be avoided compared to a new one. Should I just punt and put in an electric one?


From Don:

I had a problem similar in My 1955 New Yorker where I thought the gas was getting vapor lock, but what it turned out to be was rust in the gas tank, because it had sat too many years with only a quarter tank of gas. My solution was to take the tank off , clean it out and put a liquid liner in which can be bought at most parts stores. I have not had a problem since. You might have a vapor lock problem,but then again it might be something else altogether, just a thought, I even replaced the fuel pump because I thought that could be the source of problems.

From John:

Here are some suggestions... If the fuel pump was sitting for so long it should be rebuilt. The Antique Auto Parts Cellar should have a kit for your pump. Maybe the carb is just starving for gas. Are you sure the line filter, lines or tank filter aren't partially clogged? If you accelerate with a cold engine and the car doesn't stumble that's a pretting good indication there are no restrictions. Make sure the fuel line fittings and hose clamps from the tank to the pump are tight so you aren't sucking air into the fuel stream. You can replace the metal line from the pump to the carb with a couple of nipple fittings and a length of fuel hose. The hose will insulate the fuel and prevent it from boiling if vaporization is taking place in the line.

From Rich:

I've had similar vapor lock problems on my '50 Winsdor. A carb rebuild relieved half of the problem but not all. By re-routing the line about 1" more from the block and polishing it with steel wool helped until the 90+ days. For those occasions I place three wooden cloths pins on the line as heat sinks. No more problems. I don't like the look but it sure beats stopping.

From Roger:

I'd check the routing of the gas line from the pump to the carb. Sometimes the line was originally wrapped with an insulating cover, probably asbestos, to avoid vapor lock.

From Michael:

Most definitely if you have the original steel fuel line you should try to insulate it as much as possible from the block. My solution was to use 3/8" inch rubber fuel line hose and split it down one side so as to overlap the fuel line from the pump to the carburetor. Also make sure you have an inline fuel filter installed to help to prevent any rust from entering the carburetor. For an excellent source on antique mechanical parts such as Fuel Pumps and information on same, go to http://www.then-now.com and click on Parts, then Fuel Pumps, etc. Mucho information for all. I highly recommend them, located in Weymouth, Massachusetts. They also advertise in Hemmings Moter News. I have gone their many times since they are only 20 miles from where I live. They also can rebuild Mounts. Check out the Website!! Ph: (781)-335-8860. Also known as Antique Auto Parts Cellar (same people, different building) where they concentrate on early 1950 back to early 1900's.

Question from Philippe (1957):

Two days ago, I have a fuel pump problem. Two years ago I changed my pump because the "old" one didn't supply enough fuel when I floored the car. I bought a NOS pump on ebay, installed it and it works well....until last week-end! On the highway when the road climbed, I was out of fuel if I wanted to keep a 70 mph speed. The only solution was to release the gas pedal and not try to climb at more than 55 mph. On the flat road, there is no problem running at 70 or 75 mph. I took a look at the fuel filter and there is no problem.

So here are my questions:
- i'll install an electric "Holley red" fuel pump I bought as a spare last year. Is there some problem with unleaded gas with this type of pump?
- Where could I find a fuel pump kit for unleaded gas? I've now got two pumps to repair ...


From Pete:

I wouldn't rush to install an electric fuel pump. Too often "fixes" like this mask the real problem.

An NOS pump could very likey have failed since it is quite old. Even if the diaphragm is okay, the disc valves (suction/discharge) may have been affected by modern fuels. The discs warp and then won't seal against their seats. A fuel pressure test and/or delivery rate test will tell you if the pump is working correctly. Unfortunately I don't know who offers a rebuild kit for you pump. Any recently manufactured parts, however, should be made of materials that stand up to modern fuels.

Also, you may want to check carburetor float level. If the float is set too high you may have starvation problems during climbs.

From Rob:

The electric pump shouldn't have any trouble with today's gas. My '83 was converted and has a Carter electric pump in the back. No mechanical pump and no problems after about 5 years. I have always been told NOT to buy NOS fuel pumps because the rubber may dry out and cause the same problems as on your old pump. I don't know anything about new pumps for a 392 though.

From Dick:

Any NOS pump you buy is going to have a diaphragm that cannot tolerate modern fuel, at least in the USA. I don't know if Europe is using oxygenated fuels to meet air pollution rules or not, but if they are, you need to replace all rubber parts in the fuel system with modern parts. This means new fresh gasoline tolerant rubber for everything, including your fuel hoses. The presence or absence of lead is not the issue here, the issue is oxygenates in the fuel.

If you want to send the pump to the US, I can recommend a couple of places to do it for you, but if you want to buy a kit and do it yourself, you need to search the kit suppliers. Skinned Knuckles magazine advertises a couple of folks who sell these.

From Bill:

I wouldn't be surprised if the diaphram is shot in this one. They can dry out or dry rot with age, even an NOS unit sitting on the shelf. Nothing wrong with one on a trailered car, but on a car I am going to drive, I would use a rebuilt or new production pump of some sort. There are a number of suppliers in the US, especially given your car should be a Hemi motor if it's the '57 Imperial.

If the car is carburated, you only should need about 13 PSI (US, would have to convert for the metric equivalent) fuel pressure. Electric pumps and so forth are generally aimed at racing cars or cars with fuel injection systems. You'd want a safety shut off on that just in case if you add it to your car.

As for the lead, it only comes into play with regard to the valve seats. The presence or lack of lead should have no effect one way or the other on the fuel pump; certainly it never did in my '60 Pontiac, and I never did need to change the pump on that car. Sometimes they give us an oxygenated fuel blend, in the winter, and I hear people complain it attacks the rubber parts in the fuel system, but I never noticed any problems with it.

Your problem reminds me some of my rat car, you might look at the carbs too. I have a computer controlled carb, and it tends to have a dead spot anywhere from just a little bit of throttle on up to almost full throttle. I run it like that anyway because #1 its a beater and #2 for the cost of a carb rebuild I could buy two more cars just like it. I'm waiting to come up with the same car without a computer to rob a carb out of and fix it that way. I'm not 100% sure just what the problem is in it but it cuts out and doesn't want to run; my guess is one of the sensors is bad and makes the carb lean out.

Question from Philippe (1957):

A week ago, I put a new rebuilt mechanical fuel pump on my car. I filled the tank and started a 200 miles trip. I made it only 10 miles and at the first hard grade, the engine began to miss. I went back home w/o any problems.

This week I have tried to solve the problem which was, I was sure, the "new" pump. First I tried to start the car. Nothing!! The starting motor ran but the engine coudn't fire. I removed the output hose of the pump and found that no fuel was present if I ran the engine. Therefor, the pump was bad. I decided to re-install the Holley electrical pump but before I conducted some tests with the "new" pump off the car. I found the pump works when I made several strokes with the input hose in inverted!

So I installed (on the ground, at front, with flying wires) the electric pump. The input was at the fuel tank to the pump end (near the front wheel) and the output was in a jar. By chance (and because I didn't have another hose) I put a clear plastic hose as input hose on the Holley pump. I connected the 12V and saw that the pump delivers just a little fuel (1 pint in 5 minutes!!) with a lot of air bubbles, sometimes no fuel, then a little, with erratic flow.

I thought that the pump wasn't in "the right place". These electrical pumps must push and not pull. So i installed it at the rear, near the tank. Same results!! It can't supply fuel for a 1/18th thermic car!!!! And as before, there was air in the fuel. I thought that I had an air leak somewhere between front and rear of the rigid line so I made a pressure test: I plugged the rear end of the fuel line (between rubber hose and fuel sender unit) and applied 30 PSI at the front end of the line. No leak !!! So it seems that I have an air leak in the fuel sender tube (at the upper end because the tank is full ..) !!!

Does anyone have a problem like that?


From Brooks:

If you've got good line from the front of the car all the way up to where the sender unit enters the tank, I think you have hit the nail on the head. Sounds like the tank needs to come down. This does happen....

From Sherwood:

Regarding the fuel tank -- have you blown air back into the tank? Tank off the filler cap and blow compressed air through the fuel line into the tank. I think you have a blockage that can be removed by this method. It will not be a permanent cure bit should get you far enough to lower the level of fuel in the tank so you can remove the tank.

From Phil:

The fuel pump on big block Mopars is driven by a short push rod. Over the years, this rod becomes worn and eventually results in poor performance of the mechanical fuel pump. I checked the 1964 Manual and couldn't find a spec for the rod so I'm reduced to identifying a possible problem while lacking the ability to define it.

From Paul:

Based on my own experience, if the engine that you are working on has less then 200,000 miles on it, there shouldn't be a problem with this rod, and maybe not even then. I have 5 Imperials with 413's. All of them have had fuel problems ranging from worn out pumps, bad carburators, and dirty tanks, lines, and filters. I never ran across a problem with this rod. Two of those cars have over 200,000 miles on them.

If everything else in your fuel system is within spec, new, or replaced, and your car still doesn't run correctly I would tend to suspect an ignition problem. Ignition problems and fuel problems mimic each other in symptoms of poor performance.

Back to the fuel system, though, I have one car that had a partially clogged fuel delivery line from the tank. Although it appeared that everything was working right, the amount of gas traveling through the line was not sufficient to supply the engine properly. The fuel filter was suspected, but replacing it repeatedly had no effect. The result was misfiring at higher RPMs, and, in this case, seemed more like an ignition problem. Finally, the clog broke free and made itself obvious by clogging the new fuel filter and stalling the engine. Once the filter was replaced, the car ran like a champ.

Sorry about the "back and forth" but like I said, symptoms of problems with these two systems are difficult to separate. If the engine oiling system was ever badly clogged, or if the engine was "cooked" there would be a chance that the fuel pump rod was damaged, but not really very likely.

From Dave:

Just remove the rod and have a look at it.

A good one will have the same length of metal "turned down" a bit on each end (about 1/2" IIRC). Worn ones will have one end a bit shorter. And don't forget that the worn end of the rod will often wear away on the camshaft lobe too, so even a new one would be "short" and you would need another cam.

From John:

Have had similar problems with fuel delivery on my '65. The tank had been internally coated at one time and all of that had come loose and was lying around casually near the bottom of the tank. The fuel filter on the inlet line from the tank was long gone. I disconnected the line just outside the tank, took the line/gauge/filter out (this is done by rotating a metal ring on the outside of the tank to allow the assembly to be lifted out). My sending unit for the fuel gauge was bad and the fix for that is another story. However, relating to your problems, that piece of tubing from the filter to the connector outside the tank was very badly plugged with debris (probably from the bad tank lining material). So, first I would suggest you check the epoxy liner to make sure it's still in place where it belongs. Second, clean out the piece of fuel line (can be done with a piece of wire) and then place a new fuel filter on the inlet. Now comes the commerci! al part of this message- these filters are no longer available and I got so tired of searching that I made a small run of new ones (the advantage of running a machine shop!). These are rectangular in shape, about 1/2 X 3/4 X 6 with solid ends and 200 mesh stainless steel screen. One end is tapped for a 1/8 pipe fitting. Being all stainless, these should last forever, and can be easily removed and blown out with an airline if stuff should get lodged on the outside of the mesh.

Question from Yasushi (1958):

I imported my '58 IMPERIAL 8 years ago to Japan.  I am wondering what the life span of the fuel pump is?  Please let me know the method of repair when the pump is out of order.


From Dick:

Some times the fuel pump will fail without warning, but more often you will begin to notice a sudden loss of power when climbing a long hill, or accelerating rapidly for a long time. The car will run OK at low speeds and idle fine, but will starve for fuel when a heavy demand is placed on the engine. If this happens to you, you can always temporarily replace the fuel pump with an electric one, which you wire to the ignition terminal of your ignition switch (so it will turn off automatically when you shut the engine off). If you do this, you should take the connections off the original fuel pump so that if its failure is of the type that lets gasoline into your crankcase, it will not contaminate your engine oil with fuel.

The shop I use for Fuel Pump rebuilding is "Egge Machine Company". Their address is 11707 Slauson Avenue, Santa Fe Springs, California 90670. They will send you a catalog of all their products and services if you send them a note requesting it.

From Bill:

Fuel pumps can last a long time. Sometimes longer than many other parts of the engine. They really don't have a lot of working parts to go bad. A simple diaphragm style pump. They can be rebuilt but usually a new or a rebuilt pump are easily available at the auto parts stores and not very expensive. At least here in the US. Sometimes they will quit gradually, giving symptoms of starting and stalling frequently or leaking, which you will see the gas leak. Other times they just quit with no warning what so ever.

Question from John (1960):

Can someone tell me if the 1960 fuel pump is specific to that year or will any Mopar pump fit my car?

Reply from Mikey:

The fuel pump for the 361-383-400-413-440 is physically interchangeable. The mounting pad is the same, the pushrod is the same, the pump itself can interchange. The inlet and outlet positions on the pump itself may be different, and the " style " of the pump may be different between an older pump that is rebuildable and has the bolted together pump housings versus the newer crimped housings that aren't rebuildable. Just a FWIW, obviously a later crimped pump wouldn't be " correct" for a concourse situation, but if it means the difference between driving and towing, its good to know.

Follow-up question from John:

Its good to know that they all should fit. I removed the old pump from my '60 today, but cannot seem to get the new one into place. It seems as though the push rod needs to lift a bit higher, but its up as high as it will go & the pump doesn't want to seat. The shape of the pump arm appears identical to the old one so don't know why I having so much trouble. I just changed the one on my '69 a couple of months ago. Other then the alternator being in the way, it went together without any problem.

Reply from Kerry:

On some motors you have to remove the 3/8 Allen screw plug below the opening and push the rod up with a stick so you can get the fuel pump arm under it. Don't forget to put the plug back in.

And from Phil:

Sometimes you need to rotate the motor some by hand to be sure you have the rod for the pump off of the high spot on the cam.

And from Russell:

Try turning the engine over one full turn and then try the installation again. You may be on the high side of the cam.

Question from Frank (1961):

My car suddenly would not start tonight after sitting for a few weeks. It cranked over fine but there was no hint of combustion. I pumped the gas several times and I never smelled any fumes. I disconnected the fuel fitting at the carburetor and it was dry. I suspect I have a faulty fuel pump or maybe a clog somewhere. Are these pumps available at NAPA or other parts stores or do I have to rebuild it, has anyone replaced one of these?


From Dick:

Should be in stock at NAPA, so far as I know.  My 64's was in stock, and I'd bet they are the same. Very likely it IS the fuel pump, but you would be wise to check to see if you can make bubbles in the tank by blowing into the engine end of the fuel line from the tank to the fuel pump. Take the cap off the tank so you can hear the bubbles, and using a temporary rubber line, just blow into the feed line. It will take some push on your part, but you should hear a raucous noise from the rear. If not, you may have a plugged line (if it is hard to blow) or an empty tank (if it is easy to blow).

From Norman:

Check the short hose from the gas tank to the frame line and the one half way up the frame. I had to replace both on my '64 NYer.

From Zub:

I had problems with my electric fuel pump last year when I got it installed. The Crusier would not start in the morning or after sitting for a few hours without pouring gas down the carburetor. The problem which my friend solved yesterday is as follows: The fuel pump instructions state that you must hook up the power in such a way that the pump will start when the oil level comes up. This is a safety feature to prevent fuel from pumping in an accident. The problem with this is. The 1966 Imperial like many others of the time period, have oil pressure units that work not just on electricity but temperature. Therefore the fuel pump will not send fuel when you try and start the car after sitting for long periods. He hooked the power of the pump to a 12 volt line that only works when the key is in the on position. So when if finally stops snowing I can take my babe for a spin.

Question from Nathan (1962):

I installed a new fuel pump on my 62 4 door (413). I made sure the pushrod is above the pump arm but it does not pump. I removed it and checked the pump, it does pump when moved manually, and the push rod does move in & out depending on the crank location. It seems the rod is too short, or the arm is bend down too far. It looks the same as the old one. Is there anything other than just the push rod? Could something have fallen out? I just have a steel dowel like pushrod. Is there a roller for the end or something? Any ideas? Do I need to adjust the pump arm? How?


From Phil:

Hold the old and new pump next to one another, and check the angle of the arm. Sometimes the arms can look identical and are not. There's no adjustment, I just have the feeling that they gave you the wrong pump. Also, just in case, check the rubber hose that goes from the tank to the fuel line on the back end. If it's cracked or holed, any vacuum leak in the line to the tank, will prevent the pump from being able to draw pressure.

From Steve:

I'm wondering why you are replacing the fuel pump. Your problem may not have been the fuel pump.

The first thing that you need to do is find out if the pump is getting fuel supplied to it. I have a few feet of clear vinyl 5/16 and 3/8 hose that I use in cases like this. It is avail in Home Depot.

Put a piece in-line, between the line that attaches to the pump...and the pump. The clear line lets you SEE what is going on...and if there are an excessive amount of air-bubbles traveling with the fuel. If the pump is getting supplied with fuel, then....

Attach a few feet of the clear line to the output nipple of the pump...and the other end of the line into a clear 2-liter plastic Coke bottle. Dump a little fuel into the carburetor and fire her up. Note the condition and volume of fuel being supplied from the pump into the bottle. The bottle should be placed under or beside the car and not tediously placed under the hood. If spurts of fuel are being supplied to the bottle, your problem lies with something after the pump. (Filter, float, collapsed/plugged line)

Is this "New" pump brand-new and never used? If the pump was used at all then uninstalled and then let sit long enough for the gas to varnish-up, there is a chance that the check-ball is stuck because of the residual fuel turning to varnish inside the pump. <--this happened to me with a pump that I had sitting in my parts-shed. I couldn't figure WHY THE HECK it wouldn't pump once I installed it. I finally took it back off because it would not pump even though it was getting fuel supplied to it. I held it in my hand...said a few foul words to it, then a *POP!* came from inside the pump. I reinstalled it...and it has been working fine ever since. Weird things like that only happen to me, I guess.

...and like Phil said, there is no adjustment. There are 2 kinds of pumps that I know of. The High-Perf pump has 3/8 lines. The pump lever's are the same. There is no "roller".

Question from Zan (1962):

I went after the fuel pump this weekend. Took me 45 minutes to get it off. Took me 10 minutes to put it back on and 5 to take it back off after I think it's not working. Is the arm supposed to be able to go up and down... if so mine is stuck., but what do I know about these things. 


From Dick:

There is a push rod that tends to fall down when you pull the pump out, the easy way to reinstall the pump is to goop it (the push rod) up with grease so it will stay up out of your way when you put the fuel pump back on the block. If you did not encounter this, or notice it, chances are pretty good that it is either stuck up by crud, or interfered with your new pump and maybe even bent the pump arm. I think you need to investigate this situation. There is an access plug under the fuel pump mounting flange to provide a way to push up on the rod to hold it out of the way, this is the method recommended in the manual (which I assume you have and have studied), but that is a lot of trouble, the grease trick is a lot quicker. You say the pump doesn't work - do you mean the arm is very hard to operate? This is normal, with a fresh pump - those springs are tough in there. You may have to fasten it in a vice and use a long lever arm like a crescent wrench to operate the arm. If, on the other hand, you are saying the arm goes up and down but nothing comes through, and you know there is gas at the ready, then you have a bad pump for sure. Don't be timid about tackling these things and READ THAT MANUAL!

From Naldo:

 I have learned that there was no way to line the holes in the pump up with the holes in the block. I learned the reason was that the pump shaft had to be threaded around this 3/4" highly polished bolt or strut like thing inside the engine. No matter how I threaded that pump shaft, I could not get it so that the bolt holes aligned. I checked the gasket of the old pump against the new to assure that yes indeed the distance between the holes were identical. I read the incredibly useful factory service manual. I was flummoxed. Fast forward two weeks and I am standing in the men's room at work minding my own business when the fellow standing next to me, who I have seen here in the office but have never spoken to, starts a chit chatty conversation about the weather. I replied that yes it would be another gorgeous Houston convertible weekend and that fact was very depressing. He was confused and asked me why nice weather would be depressing. I explained that my convertible was down for the count and I couldn't figure it out. A lousy fuel pump, for crying out loud. It turns out the chit chatter is an ex pit crew member for a Mopar racing team!!! I drew a picture on a paper towel of my problem and he says that's no strut, that's the push rod that moves the fuel pump arm up and down. You have to hold that up and out of the way when you install the pump. He recommended that I take a hack saw blade and bend it 90 degrees to hold that shaft up while installing the pump. That was the solution and it took less than five minutes to put the pump on. Yes, Zan, the pump arm must move up and down but it won't if you are somehow able to install it without that push rod, strut thing properly positioned. It takes a fair amount of force to manually move the arm but any adult male should be able to do it.

Question from Zan (1962):

I managed to take the fuel pump off my sixty two which I suspect has some of the rust that has been getting in my fuel filter. How do I clean it out?

Reply from Dick:

If it has a removable cover over one side of it, just unscrew the center cap bolt and it should show you the filter screen which needs to be cleaned out. If you can get to it, just slosh it in some solvent ( I use kerosene, but gasoline will do it as well, although it stinks and attacks your skin, and is much more flammable). If your pump is crimped together with no provision for cleaning it, you're stuck because the internal valves will keep you from flushing it out.

Question from Kerry (1966):

Had a bizarre problem on my '66. It has been having an obvious fuel delivery problem recently. Would stumble off idle, starve for fuel if left idling a long time. Did not want to pick up fuel, etc. I had a lifetime Autozone fuelpump on it so I pulled it off and got a new one. Put it on and no pumping. Humm, maybe I missed the rod, Off, feel the rod, reinstall. Cuss, repeat. Pull the allen plug and try and get the rod out. Cuss some more, stick a magnet in and get the rod. Humm some wear on the top. Grease on the top to hold it up. Reinstall the pump. CUSS. About this time I thought it wasn't moving very much and seemed to be 'high' in the chamber so I pulled the rod from a spare engine. When I pulled the one out of the car I was AMAZED to see it was nearly 1/4" SHORTER. It is obviously worn down as the rod has a slight step turned on each end and on the shorter one it was 1/2" on one end and 1/4 on the other. Replaced the rod with the long one and it's fine. This motor had a professional rebuild before I bought the car. EVERYTHING supposedly. I can't believe the cam is worn because the car was still running. What would cause the rod to wear that much??? I guess if the lobe is worn and the pump quit's pumping again, I'll just install an electric fuel pump and forget it. Thoughts?


From Roy:

Since fuel pump flanges are all very similar even if the fuel pumps themselves are not, I suspect someone at one time put one on that missed the specs by a small margin and ground down the rod. The other possibility is that when the pump was replaced at one time, the lobe was on the extreme high side and instead of thinking to bump the engine, somebody ground down the rod to get the bolts to catch a thread.

From Dick:

My guess would be that the camshaft is not installed properly, or perhaps a replacement cam was used which does not provide for lubrication of the fuel pump cam, either due to a mistake on the cam design, or due to improper assembly/manufacture of the cam.

From Rob:

I don't remember this being that uncommon. I remember when I did the pump in my 440 (going on 15 yrs now) they told me to check the length of the rod. I think they make it softer than the cam, so the cam wouldn't wear out. I could swear I've heard of this, although nobody I know has personally had the problem.

From Pete:

I've heard of this problem before. Someone on another list (MML maybe) posted links to a pic of the pushrod from his 440 Cuda, I think. In that case, I THINK the pushrod was a new Mopar part and it failed in short order. The guy investigated and found out about a bad run of pushrods. I can throw the question out to the lists I'm on and see if the guy responds. BTW, this is a VERY common problem on the early '60s Elwood Engel Lincolns. On the 430 in those cars the pushrod has a bronze tip that wears to a certain point and then breaks off.

Question from Dick (1967):

Our 67 LeBaron runs perfect on level ground, but when climbing long grades it stutters and stalls ........Any ideas besides fuel pump ???

Reply from Dick:

Sounds like fuel pump, gas filter, or restricted fuel pickup/line to me. The other, more remote possibility is too low a float level in the carburetor, but these don't change by themselves, normally.

Question from Marcus (1967):

I need some technical advice regarding the fuel system on my 19 67 Crown . I have a fuel filter in front of the fuel pump and in between the fuel pump and carburetor. Does this, in anyone's experience, have an adverse effect on the drivability ie. pinging etc.?

Reply from Dick:

If everything else in the tank and fuel plumbing system is in good shape, and you are sure there is no deterioration of any flexible fuel line (by that I mean the rubber hoses, wherever they are, have been replaced within the last few years with fuel hose rated 30R-7 or better), so that you can be certain that the fuel pump cannot suck air through a pin hole leak on the vacuum side of the pump, then there should be no problem in putting a fuel filter prior to the pump. If these conditions are not met, you may experience "vapor lock" in high temperature situations due to a pin hole leak in the vacuum side of the pump. The filter between the fuel pump and carburetor will cause no such problems, so long as it is not located near a source of high engine heat (in other words, keep it near the carburetor or in the original factory location in front of the block if you can). Pinging would not be caused by these filters, that is a consequence of faulty engine timing, high temperature, or cheap gas, amongst other possibilities, but not filtered fuel. If you suspect the factory fitted filter of falling down on the job, I'd say step one is to replace it. If you are concerned about the sock over the pickup tube in the tank having failed, then you may need to add one prior to the pump. You will be warned about crud coming through from the tank if you see a rusty colored dust in your old filters when you dump them out.

Question from Greg (1967):

What's the trick on re-installing the fuel pump on a 440? I cannot get the "rod" to retract that pushes against the lever on the fuel pump... and the pump won't go back on! Any suggestions?


From Dick:

There are two ways to do this. The easiest, if it will work for you, is to slather some chassis grease on the rod to make it stay up out of your way long enough to sneak the pump lever arm under it. If you are quick enough, that's all there is to it.

If you can't make this work for you, there is a plug right in line with the rod, sticking out the bottom of the block (that is how they machined the hole), and you can remove that plug temporarily so that you can hold the rod up with a small took while you insert the pump lever from the side. Be sure to seal the plug when you reinstall it, as these will leak oil if they are not sealed.

From Roger:

To aid in reinstalling the fuel pump, pull out the pump rod and coat it with wheel bearing grease. There is a plug just below the pump opening which will allow you to remove the rod. You may be able to reach in and put the grease on the rod without removing it. When you push the rod back up in place, it will stay put long enough to let you put the pump in place.

If you do remove the rod, examine it carefully to make sure it hasn't worn. When we put the 413 back together in my 300L, I had to replace several "failed" fuel pumps until we discovered that the rod had worn and thus was too short to make the stroke.

I know this could all be taken the wrong way in a different context--just keep your minds out of the gutter......:)

From Mark:

Don't force it on, try turning the engine by hand a little and then try it.  Make sure and disconnect the battery first.

From Dave:

I had this same problem when I replaced the fuel pump on my 1973 Imperial last summer.

My solution was to crank the engine in brief spurts until the rod would retract farthest up into the block. This required sticking a finger in the hole and pushing the rod upwards to check the distance. Don't crank the engine with your finger in there, of course.

Some books suggested globbing grease around the rod to help hold it up and out of the way. I tried this, but the rod always fell down by the time I had the gas pump in position.

Finally I used a one foot length of foam insulation tubing, the stiff narrow kind for pressing into crevices around home windows, to hold the rod in place. The tubing left just enough room, and compressed just enough, that the pump lever could be put in place loosely, and then the insulation removed.

Removing the tubing was a matter of being careful not to rip it and not to drop the fuel pump.

My installation was successful. Perhaps this technique will work for you.

From Phil:

Dick has got this situation exactly right, but every now and then, the engine will stop with the cam turned where you can't retract or push up the fuel pump rod. All you need to do to get the rod to slide up in, is turn the engine by hand about a half turn or so, just enough to get rod off of the high spot on the cam, that actuates the fuel pump rod. Don't be surprised if you still have to do exactly what Dick suggests after you turn the engine, cause with no tension on the rod, it slides in and out fairly easily.

From Steve:

Take it from someone who has installed MANY a 440,383,etc fuel pump... Use the lever-end of the pump to catch the varnished-end/ridge of the pump-pushrod. Push the rod up into the block with the fuel-pump...then release just a bit to let go of the varnished ridge. Then quickly push the pump in the rest of the way before the rod slides down again. I hope I described this right. In the time it took me to type this, the pump would be in and bolted up.

I always push the rod up with my finger to see/feel that it goes in all of the way with the varnished-ridge (about 1 inch?) sticking down. If it feels like the shiny part sticks down a little, turn the engine over a bit. I just grab the alt-belts from the pass-side and PULL!

From John:

The rod should go back in with no problem, its keeping it there till you get the pump in place that's the real pain. If this happens, I put a little grease on it so it stays long enough to set the pump.

Question from Ed (1968):

I began with a car which would hardly idle. Black smoke pouring out of the exhaust, and the looping idle was impossible to maintain, all the while, drinking gas like crazy and the crank case filling up with that gas. Totally undrivable.

I am doing all the work and I have accomplished the following things over the last couple weeks:

I have replaced my in-line fuel filter, oil and filter, pcv valve, plugs (autolite 85's) and freshly rebuilt Holley carb. Already had a new set of wires, points, which I reset, and dist. cap. I tuned it and set the timing by feel, probably not the best way but I haven't got a timing light and I'm not sure that it would be helpful for a car this old.

I was able to drive the car for about 20 minutes, today. The smoke is better, but there's some in the engine compartment. (am going to check valve cover gaskets) Idle is better, but there's a point starting out from a dead stop where the engine coughs then goes. Basically, it coughs a lot when I hit the gas.

More interesting, the new in line filter is clear. It isn't filling up with gas. There's a trickle going in and that's it. There are no gas leaks and the crank case isn't filling up with gas anymore. That's a good thing.

Could it be that I have a defective fuel pump? Is there a filter which could be blocked in the tank on a '68?


From Robin:

Your pump could be bad, can check by feeding the pump from a jerry can or something similar. If the pump is good it will fill that filter up right away. Had similar problem with my '78 Chevy truck. Pulled the tank and looked fine but while the tank was out I replaced all the rubber fuel lines. Fixed the problem. You could very well have a partially collapsed rubber fuel line.

From John:

This sounds like its starving for fuel. Try simply removing the gas cap & see if the filter fills up then. You should have a vented gas cap, if not, this could be the problem. It would also cause the tank to collapse.Otherwise, there could be a lot of crud in the tank thats blocking the fuel line.

From Joe:

I had the same trouble. The diaphragm in the fuel pump was cracked, sending gas into the motor's crankcase. It smoked like hell and it got about five miles to the gallon. After I changed the pump, there were no more problems.

Question from Roger (1969):

I am changing fuel pump on my 1969 Imperial it was a bear to get off back bolt. I am having a devil of a time putting new unit on the bolts want to bind on unit can I open these holes up a little bit? what kind of tool have any you have used to get on back bolt or suggestions would be very helpful.


From Dick:

You are aware, aren't you, that a plunger descends into the pump arm entry hole when you remove the old pump, and it will prevent you from lining up the new pump until you move it back up out of the way? If you haven't found it yet, there is a plug in the block just under the pump mounting flange which is placed there to give you access so you can push the plunger back up out of the way with a long thin rod (screwdriver?) while you reinstall the new pump. Sometimes these plugs are Allen head, some times they are normal looking pipe plugs, but be sure you are looking directly under the center of the pump opening. Another trick which sometimes works is to push the plunger up after coating it with heavy grease, if it is going to work it will keep the plunger from seeping down long enough for you to cram the pump in there. There should not be any problem lining up the bolts when this is all taken care of.

From Roy:

It also helps to make sure the engine did not stop with the fuel pump pushrod (sometimes called a plunger) in the extended position which would mean you would have to compress the pump-arm by cramming the pump into its hole....while trying to start a bolt at the same time. "Bumping" the engine over just a bit with a remote starter or by the ignition key with the coil wire unplugged will solve the problem....if indeed it stopped with it in the extended position.

Question from Roger (1969):

A couple of questions; first, if I put on a new electric fuel pump, do I need to take off the mechanical unit?  And should the fuel line to the carburetor be metal?

Reply from Brad:

I would take off the mechanical pump. The mechanical pump will certainly develop a failure running dry. Besides, it makes an annoying 'wooka wooka' sound if you don't remove it.  Metal line would be good. Non-metal line would be fine as long as it is tied up away from hot parts.

Question from Mark (1971):

Anyway, yesterday I changed the fuel pump on my '71 and I had a heck of a time getting the bolt that's closest to the engine block into place while keeping the fuel pump lined up properly (I forgot my third hand that day). I even resorted to using a piece of chewing gum in the end of a socket to hold the bolt in place (didn't work)! Finally got it in there by lining it up as best I could and tightening down the other side. But they just don't give you much room there! Was wondering if there was an easier/surer way of doing it?


From Bruno:

Instead of a bolt, use a stud. Easier to put the nut on then to find the threaded hole with a bolt.

From Ross:

Don't know if there is a simpler way to do the job of changing the fuel pump. The first week the The Tan Sedan became mine I replaced the battery, battery cables, starter and fuel pump because I knew all of them to have been themselves replacement parts and I wanted no surprises after changing ALL of the fluids and filters after a major tune-up. Luckily I changed the pump last . . . and felt just the way you did, cursing myself for changing something already working. (But not so sorry as to be glad of it 40m miles later). My attitude is that the easier I think the job is going to be, then an inverse amount of difficulty will attain. Sure there is an easier way: With the car on a lift, holler over to your service manager with 30-yrs Mopar experience to show you how to use the slick tool he welded up from scrap for just this job . . . .

Follow-up from Mark:

My fuel pump actually did need changing - it was leaking - so I had to do it, but I think now I would get a long rod or something and just stick it through the left side to make sure I was lined up right, and THEN tighten the other side up. As for the suggestion to putting studs there, the block already has holes cut in it there for bolts, so I was sort of forced to use the bolts . . . unless there's a way to replace with studs??? . . . but yes, you are right, that would be easier.

Question from Gary (1981-1983):

I need a fuel pump for an 82 ------ any suggestions? They are no longer available from Chrysler!


From Todd:

I understand that the fuel pump is a two parter. One piece in the tank and  the other at the engine. Are you looking for one or both parts?

Follow-up from Carmine:

You are sorta right. There are two pumps in the system. But only one is a "fuel" pump. (The one in the tank). The other pump is called the "control" pump. It's located under the air-cleaner, and from what I've heard it rarely goes bad. It's job is to re-pressurize and meter fuel for the system.

From Bob:

I have replaced my in-tank pump, for which I could not find a NOS replacement, with an external 5.0L Ford Mustang fuel pump. Advantages: cheap, easy to find if it fails again, easy to do. Disadvantages: not stock, makes a bit more noise than the in-tank pump.

From Carmine:

Hate to sound like a commercial, but I recommend a guy named Dean Sanders in Warren, MI. He has 30+ '81-'83 Imperials that he is parting out, plus an assortment of NOS parts. Call him @ 810-979-8035. Tell 'em Carmine sent ya. I hear LOTS of bad stuff about Brad's NOS parts on the MML (Mopar Mailing List). I can't say bad or good as I have not dealt with them personally. I do know that the want over $400 for NOS stripe-kits for '81-'83 Imperials, and I'll be darned if I'll pay that kind of money for 15-year-old vinyl stripe tape!

Question from Rolland (1981):

I would like some help on my '81's fuel pump. I have diagnosed the problem as a faulty pump and the IML has again come through with a suitable
replacement from NAPA. With the recent discussion I am wondering if I have correctly diagnosed the problem.

Here are the symptoms:
1)  Car will not start. By pouring fuel in the throttle body it will start and run a short time.

2)  There is no sound of a pump running at the rear. I have always heard the pump run for a couple of seconds in the past when I first turn on the ignition.

3)  While trouble shooting, however, the pump did run on one or two occasions. The car did start without priming but ran only a short time before it died.

4)  When I connect a voltmeter to the single wire connector at the tank I read 11+ volts when cranking the starter.

5)  I have also checked the voltage at the fuse block and read about 11.5 volts when cranking.

This sounds like an electrical problem within the fuel pump. However, the comments made in the last two days suggest these are very reliable pumps and possibly it could be plugged from a defective inlet filter or something else.

Consistent with the universal laws of "in tank" fuel problems the pump failed right after filling the tank so if I can get it running I would rather burn out those 20 gallons than drain and store them.

Any comments or suggestions from the 81 experts?


From Bob:

The simplest test for the In-Tank pump is its' output pressure; attach a pressure gage to the supply line under the hood and have someone crank the starter and read the pressure - should have at least 12 lbs. Since you are getting battery voltage to the pump, as measured at the pump, it is either electrically "out" at the pump or the pump is locked-up. There has been a suggestion to replace the filter sock at the pump intake - not a bad idea, but go further and evaluate the pump. They can get clogged and the innards are such that it'll be very difficult to clean - it is a three stage impeller system, closely toleranced to keep the fluid moving up and to reverse flush it would be questionable.

From  Dick:

The fuel pump in the tank is automatically shut down immediately if the engine is not running. This is a function of the ASDM, which monitors the ignition pulses, and if 150 milliseconds passes with no ignition pulse, it drops the 12 volts to the in-tank pump immediately, for obvious safety reasons. So your inability to hear it running is normal if the engine doesn't start right up.

To test to see if the in-tank pump is OK, run a separate wire to the big resistor on the firewall (the one with two heavy dark green wires, white and rectangular in cross section), momentarily connect to either wire, and to your battery directly, with the engine off. You should hear the pump running in the tank.

If you pull the hose off the fuel filters (you have changed these, right?) under the passenger door, you should see about 13 PSI into a pressure gauge, and if you let the gas flow unimpeded, you should see about 1 coffee can full in maybe 15 seconds. If all this checks out, your problem is elsewhere.

Have you checked the dreaded fuel pressure switch yet? Closed resistance is the bugaboo for these, it should be less than 10 Ohms. Replacements are available from "Jegs" for about $14!

Back to the in-tank pump for a moment: The usual complaint about these is that they get extremely noisy when they get old, especially if the owner has habitually let the tank run near empty, as it is the fuel itself that provides the cooling for the pump.

Don't go to the trouble of draining the tank and changing the pump until you verify that it has failed, as described in Paragraphs two and three above.

Follow-up from Rolland:

I have gone through the tests. I cannot get any fuel out by breaking the line behind the filters. I heard the pump running before I removed the tank this morning and when I disconnected the line behind the filters there was no fuel. When I removed the pump and immersed the pump in gasoline it would not pump out the outlet tube even though the pump was running. After repeated tries I got fuel to come out of a hole in the plastic cap where the electrical connections fasten. A pretty good stream came. By intermittently applying power I was able to get a good stream of fuel out the outlet hose. Then it stopped again and there was no motor noise. It appears to be an intermittent electrical problem within the pump. Perhaps a stuck brush or a broken connection. I am going to replace the pump if I can find one. I really don't want to put that tank up again with the old pump. I called the Imperial Wizard in Colorado and there was no answer.

Reply from Dick:

Sounds like you nailed the problem, all right. I have heard very bad reports on the "Imperial Wizard", but I don't have any personal experience with him. When my pump cracked it's housing, I was on US 95 in the wilds of northern Nevada, more than 50 miles from the nearest town. I managed to limp into Boise, where I found an external type pump for a 5.0 Mustang had similar specs. I mounted that to the body in front of the tank, laying on my back in the gravel by the side of the road, and managed to mickeymouse some plumbing fittings to go into the tank and dip into the fuel - I drove the car that way for 12 years! So it isn't rocket science, you can make almost anything work, as long as you get around 60 GPH and 13 PSI out of it.

Follow-up from Rolland:

Thanks for the NAPA number and the information on the 81 fuel pumps. I looked over the pump you recommended and I believe it will work OK. I spent some time with the NAPA people and I ended up buying an Air Tex E8094. I would be $70 richer if I had followed your recommendation however. The pump I purchased was $161 but it is nearly a "drop in". The electrical connections are the same as the original, the pump diameter is the same, and the inlet diameter fits perfectly to the hose that connects to the filter. The outlet size is 5/16 rather than 3/8. I used a new 5/16 hose to replace the molded hose. The somewhat shorter pump allows a generous radius on the hose and it fits up well. The pressure is 16 psi which I believe compares favorably with the original pump. I am not sure on the flow rate. I installed the pump this afternoon and the car seems to work fine, although I only drove it a couple of miles. I will probably get out on the highway in a day or two and let the club know if there are any problems. I expect the pump you recommended would have worked equally well but I was a little concerned about the modifications.

Question from Rolland (1981-1983):

I wasn't aware of the flow requirements for the 81 fuel pump.  Is it 60 gallons per hour? That seems like it is many times too large. Could you ever use more than 10 gph.  100 mph at 10 mpg would be 10 gph. Maybe I am missing  something.  I think this Air Tex pump is made for in tank or external mounting.


From Bob:

I think Dick mentioned the 60 gph flow rate; the first pump number that I mentioned is rated at 29 gallons per hour at 12 pounds pressure- which I believe to be the correct amount for initial Start-Up.. Of course we must remember that after the initial "thunk" the pump voltage is reduced by half and so both discharge pressure and flow rate are appropriately reduced to around 7 psi and a lower flow rate. I'm not certain what the specs are on either the pump you got or where Dick got his numbers. If the flow rate is that high after the engine is started I would think that to be most excessive and one heck of a large amount of gas being returned to the tank. That was why I mentioned the other pump number - it related best to the original Chrysler parameters.

From Dick:

I picked up the 60 GPH rating from something I read in the technical service manual. It was making the point that a large excess of fuel is supplied to the control fuel pump system so that the fuel is kept circulating in high enough volume that the engine's demand will not materially affect the flow rate, thus the cooling provided by the circulating fuel prevents vapor lock and pump overheating for the control fuel pump. I'm sure the car will run just fine with less oversupply, but I don't know how much is not enough. If the car is climbing a long hill and accelerating, it might get at worst 5 mpg for a few minutes, that means it will consume at the rate of 12 GPH for that period at 60 MPH. I suppose they set the intake pump capacity such that there would still be a great oversupply even under those conditions, and even with a somewhat degraded pump and filter assembly, and on the reduced voltage of during normal operation. I'd guess you could fit the 29 GPH pump and never know any difference.

Follow-up question from Rolland:

Do you have the initial specs for the Chrysler pump? I understand from my service manual that the pressure should be between 12 and 15 psi but I don't recall seeing any flow numbers. Dick Benjamin gave a yardstick measure of a "coffee can" every 15 seconds." Of course this is not intended to be a specification but depending upon whose coffee can it could easily be up to 60 gallons per hour. This rule of thumb measure was without any output pressure. Measuring flow at 15 psi outlet pressure would substantially reduce the flow. I am curious to know what Chrysler used as a flow rate and under what outlet pressure conditions.

Reply from Dick:

You're right, this was not intended to be a precise measure. By "coffee can" I meant the "one pound" can of coffee, which these days is about 13 or 14 OZ. As I said in my previous posting, I don't think this is a critical requirement, given that you get at least 25 GPH or so. This would be without any restriction to flow.

Question from Rolland (1981):

I seem to remember that someone had suggested a source or an acceptable replacement for the electric fuel pump used on the 81 Imperial with EFI. Anyone have a pump for sale or know of a source. Mine seems to have died.

Reply from Bob:

The correct Fuel Pump for the EFI Imperial is available from NAPA under their Part Number: P-74051, for less than a hundred dollars. The body of the pump is smaller than the Tokheim, but has identical output capacities and will fit nicely into the existing bracket.

Follow-up from Rolland:

I just came back from NAPA where I compared the P 74051 with mine. The inlet size is smaller, the outlet tube is smaller, the electrical connections are different and the pump is considerably smaller.  I am curious whether anyone has adapted this pump to an 81 or if perhaps I have the wrong part number. It looks like a lot of modification. I don't mind adapting if it works good when I am finished.  Any experience with this pump? Any other suggestions for replacement pumps for the 81?

Reply from Bob:

I spent well over an hour searching the NAPA "Big Book" for In-Tank fuel Pumps. They have a large selection of pumps, mostly manufactured by AirTex. I took Imperial EFI requirements as to output pressure and flow rates and that pump number was the only one that offered those items plus, after looking at it, I knew it would fit into the mounting frame. Yes the connections are different and yes, the pump motor and body are very different, but it will perform just like the original Tokheim. I would like to refer to you the AirTex people who are probably the largest manufacturer of these things in the country and their number is: 1-800-424-7839 I would appreciate your response since it'll be good info for the IML group that have had difficulty with this item for years. The AirTex web page shows one of these in a Chrysler Tank mounting just like we need.

Follow-up from Rolland:

I looked over the pump you recommended and I believe it will work OK. I spent some time with the NAPA people and I ended up buying an Air Tex E8094. I would be $70 richer if I had followed your recommendation however. The pump I purchased was $161 but it is nearly a "drop in". The electrical connections are the same as the original, the pump diameter is the same, and the inlet diameter fits perfectly to the hose that connects to the filter. The outlet size is 5/16 rather than 3/8. I used a new 5/16 hose to replace the molded hose. The somewhat shorter pump allows a generous radius on the hose and it fits up well. The pressure is 16 psi which I believe compares favorably with the original pump. I am not sure on the flow rate. I installed the pump this afternoon and the car seems to work fine, although I only drove it a couple of miles. I will probably get out on the highway in a day or two and let the club know if there are any problems. I expect the pump you recommended would have worked equally well but I was a little concerned about the modifications.

Reply from Bob:

I've talked to Airtex - the manufacturer of the E-8094 pump - and they say it is NOT an In-Tank Pump - that it should be mounted externally, close-by the tank top with a filter in between. I like Rolland's idea better, especially since it will fit into the existing bracket and it required little to no modifications to have it fit and work. I don't need one for myself, but for the benefit of the IML group, I would like to know how Rolland's is running submerged in the gas. I also found out the specs on it - the pressure output is 12 to 17 psi, the volume is 45 to 50 gallons per hour, I still think that's a lot - we're looking at almost a gallon a minute, (but that is not at the normal run speed). But even half of that seems high. By the way, the P-74051 is made by Carter. For the benefit of all the EFI "Purists" I think some more comments would be a benefit....

Further follow-up from Bob (June, 2001):

The correct In-Tank Fuel Pump replacement is available at NAPA; part no. E-8094.Last time I checked, it was around $84. It fits on the cradle, is about 5 1/4" long and 3 5/8' over the insulation. You should use your old insulation sleeve on the new one. The specs on the new pump are 45-50 gallons/hour, 12 to 17 PSI output. Use care with the fuel level float gear upon removal. If your old pump still works, you can connect it to the battery and pump almost all of the remaining fuel into a container.

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