View Full Version : Fuel pump replacement instructions

06-24-06, 11:33 AM
Fuel Pump Replacement- (1994 Eldorado)

I recently purchased a nice 94 Eldorado. It performed well when I test-drove it, Carfax showed it as a one owner, it was exceptionally clean, and all the electronics worked inside and out. The next day after purchasing it I noticed it was hard to start in the morning. After the initial hard start, it ran like a top, never failing to start with one try. I hoped that a good tune-up was the answer (OEM plugs, wires, air filter, pcv valve and fuel filter), but it wasnít. After researching this site for a solution to my hard cold starts I tested the fuel pressure and found it to be at 35psi instead of the 40-50 range required. After replacing the fuel pump it starts with one tryóhot or cold!

- The less fuel in the tank the better. I was fortunate enough to be able to drive mine until there was less than a quarter of a tank left. I donít know how to siphon gas out of a fuel tank nor would I have attempted to. If you have to do this be extremely careful!
- Donít smoke or have a phone or any spark source near or around you during this process!
- I had someone help me steady the gas tank during the removal process.
- Relieve the fuel pressure. *Note- There are two ways to do this, one is by using some type of bleeder hose fitting at the fuel pressure connection in the engine compartment and the other is to remove gas cap, take the 20 amp fuse out of the engine compartment fuse block and starting the car and letting it run until it dies. I had a problem using the fuse method for this procedure. I had removed the fuel pump fuse three times prior to doing the pump removal. Once was to change the filter and then two times to check the pressureóno problems. Both times the engine wouldnít even start. This time however, the engine started and ran poorly but never died. The service engine soon light came on and it threw a code P020 (open fuel pump circuit). After shutting it off and starting it back a few times it finally died but when I disconnected the fuel lines gas spewed out everywhere so in reality I never really relieved the pressure.
- Disconnect negative battery cable.
- Raise vehicle on a lift or in a safe manner and secure on jack stands.
- Disconnect electrical plug on the rear of tank. This has a blue safety clip that is hard to negotiate. Once the blue clip is moved up, it unplugs easily.
- Disconnect fuel lines (both are at the filteróone goes into the filter and one is above it, which is the return line). Have plenty of old rags and a container to catch spills. This is also the point at which fuel vapors will become an issueóBe careful!!!
- Put a floor jack under the fuel tank. I used a block of wood between the tank and the jack. There is a flat spot on the bottom of the tank and that is the area that I used to support the tank. Raise the jack and wedge until it just touches the tank.
- Remove bolts from rear exhaust heat shield and move as needed. (I couldnít remove it completely)
- Remove tank straps (two bolts per strap).
- Slowly lower jack and tank. Have your helper watching and steadying the tank. It will have to be moved slightly to the driverís side because of the exhaust shield. *Note- The tank will be held up in the rear by the fuel filler and vent pipes so the front will be the part of the tank that lowers the most. Go slow!
- Vacuum the top of the tank and pump if possible using the brush attachment so as to remove any dirt and grit before removing pump. I also used a damp rag to wipe this area.
- At this point I was able to see the pump I.D. code on top of the pump that the parts house required to order the correct pump. There are three codes for my 94 model: EPV=$300.00 (complete assembly) or EPT and EPW= $100.00 (pump only). Mine was the more expensive complete assembly.
- Disconnect the electrical plug at the pump; this also has a blue safety clip that is tricky to get up.
- Disconnect the two fuel lines.
- Use appropriate tool to remove locking ring. I used a flat head screw driver and a small hammer, but there is an actual tool available to remove the ring. After one or two hits dirt will have loosened and fallen around the ring onto the tank, so use several damp paper towels to clean the area again. Hit the ring a couple of more times and clean the area again and then completely loosen ring.
- Lift the pump assembly up as far as possible and then lean it over to negotiate the fuel sender float out with the pump. Look at the position of the float on the new unit and use this as a guide to remove the old pump.
- Put new assembly into tank. The rubber tank seal is already around the new assembly and once you have negotiated the pump into place slide the seal down and around the tank opening and then slide the pump the rest of the down and tighten the locking nut. Be sure not to pinch the tank seal.
- Install the electrical plug at the pump and the two fuel lines.
- Put everything back together. Now would be the time for a new fuel filter!
- Replace fuse and reconnect the battery.
- Refill with several gallons of gas if necessary.
- Turn ignition switch to the run position, but donít start yet. Listen for the pump to activate and turn the key off. Turn the key to ďrunĒ again without starting and get out and look around for any leaks. If no leaks are found get back in, turn key off and then start the car.
- Remember to let the car relearn its idle (wheels straight, accessories off, let idle 15 minutes, put foot on brake and put in gear, let idle 3 minutes, leave foot on brake and car in gear and turn the automatic climate control to the auto position and wait another 3 minutes then shut the car off. Get out and check for leaks again and then take it for a test drive.

06-25-06, 01:59 AM

Good job! Why don't you copy this over to tech tips section where it can be found easily?

06-25-06, 04:38 PM
Thanks for the info how about a pic of the car:thumbsup:

06-26-06, 08:20 PM
great howto and pictures are always great!! thanks!

11-21-06, 06:21 PM
Thank you very much for this write up. Good job

11-24-06, 09:23 AM
Didn't you need to remove the gas filler and such? It was the most difficult part for me. I even didn't try to remove the pump without pulling the tank out from the car... But it is good to know it is do-able without removing it from the car.

One thing I did to empty the gas tank was to install a piece of wire instead of the relay (so that it would keep running while the key is ON) and disconnect the fuel line at the fuel filter and catch gas there. Obviously, it will not work when the pump is completely dead...

Did you check the fuel pressure when you disconnect the vacuum line to it and it was 35 psi? I believe it was a good idea to replace the pump, since it was 12 yrs old, so you will be able to enjoy driving without worrying about the pump failure for long time, but I don't know if it was absolutely needed to replace the pump at this time...

My fuel pressure regulator said its nominal pressure is 42 psi. And it will not develop 42 psi, unless no vacuum is provided. Otherwise it is more like 37 psi or so after changing fuel pump, filter, and FRP...

12-15-06, 10:38 AM
This is good info

02-03-08, 11:10 PM
I've since sold this baby. It was a one owner rust free Texas jewel and she would flat move! A week after I bought it a woman saw it and said she'd give me what ever price I asked. I kept it several months and the woman kept after me to sell it so I priced it high and she didn't even blink. She purchased it the very next day and I made $1200 profit. She still has it and loves it!

02-04-08, 10:27 PM
So, where does the fuel pump replacement come in?

02-10-08, 01:21 PM
On my 1993 Eldorado, 4.9L, I replaced the fuel pump from the top without dropping the tank. It involved cutting a hole in the floor board. I know this was a very non-traditional/unorthodox method (required because my condominium rules prohibit jacking up the car in the parking lot), but it ended up being an easier method then dropping the tank.

In any case, information and pictures can be seen in the threads of the links below:



02-15-08, 11:49 AM
That looks like a near twin to my 99 Suburban fuel sender/pump assy.

Note that GM has lots of issues with insufficient wiring/connectors and inspect carefully. IF there is melting present, REPLACE the wiring. Many parts stores have replacement connectors, some pumps even come with it. I would be willing to bet more pumps are NOT bad and the wiring is, but the pump likely could be still good. Or might have reduced life due to the lower operating voltages, so it ran in an inefficient manner for too long.

02-21-08, 03:00 PM
This is a good post... good info. Nice job.

In addition to your warnings about smoking, I see you have a worklight present in that picture... appears to be red, with the sealed flourescent style bulb....

I might also caution people to only use that sealed style of light.... the old "light bulb in a cage" style is really not safe in an environment where vapors could ignite...