red_89_vette

I'm hearing a weird wine coming from somewhere underneath the passenger side of my 89. Someone told me it might be the fuel pump? How hard is the fuel pump the replace?

85vet

Fuel pump is in tank, not a hard job. Possibly the sound might be travelling.
You should hear the pump prime your system when you first turn the key.

Give a little more detail and perhaps others will chime in.

Skippy Stone

Hey 85vet, do you remember which way the sock-filter faces inside the tank? I couldn't remember and my fuel pick-up has been sketchy since I did mine.

thanks

Mark L. Warner

I've done it twice. It's not hard, but I did have trouble finding a new gasket for the top of the tank. The sock runs lengthwise same as the car.

85vet

Mark is correct. You can get the gasket from zip products. They are a supporting vendor and you can take 10% off if ordered through forum.

red_89_vette

Well it would be my cousin helping me do this. He's done his fuel pump in his firebird formula before and he didn't have any trouble. I think it might be the cause of the whining noise. The noise is bad till about 2300 RPMS in first, but then it cuts off. It usually does it pretty loudly when the car idles, but it will do it sometimes when the car is accelerating off the line.

Where abouts is the fuel pump, like do we have to drop the tank and to get to it? Can anyone give me instructions and steps for how I would go abouts doing this?

thanks for your help

hippy

You get at it thru where you fill up with gas. That assemble comes off to get at the pump.

scorp508

1. Remove the fuel pump fuse.
2. Start the car and let it stall from running out of gas.
3. Remove the gas cap.
4. Try to start the car for 10 seconds.
5. Remove the rubber gasket thing around the filtler neck.
6. Remove the 4 torx bolts holding the filler plate down.
7. Yank the filler plate.
8. Unplug the wires.
9. Remove the 3 hoses from the plate making note of where each one goes. Careful, the supply line may have gas in it still, so have a towel handy.
10. Remove the 10 or 12 bolts holding the assembly down.
11. Pull the assembly up and out.

It is pretty straightforward from there. :)

65Z01

Unlike the F-body you don't have to drop the tank; that's why it's a piece of cake (maybe the easiest repair on the C4).
-buy an AC Delco pump and pickup screen
-remove the filler door and rubber boot
-unplug the connector to the fuel pump and crack the gas cap loose
-disconnect the three gas lines and cap if necessary to prevent seepage
-remove the ring of bolts around the retainer ring and lift the pump assembly straight up out of the tank.
-note orientation of the pickup screen and follow directions to install the new pump and pickup.
-reverse the above procedure to wrap it up.

Plan on 1/2-1 hrs for his job.

red_89_vette

ok, just tested the fuel pressure with a gauge on the test port. Key on the pressure is only at about 20psi, after extended cranking it fires at about 40psi. I'm assuming the fuel pressure should be similar to my cousin's on key on (40psi). So we're thinking it's the fuel pump. Anyone agree/disagree? Could it be a leaky injector?? I doubt it since the pressure seems to hold at 20psi when you turn the key on.

We're almost positive it's the fuel pump just wanted to hear what you guys have to say. Thanks in advance.

hippy

20 is real low with key on.

Skippy Stone

That could mean a leak anywhere-not necessarily the pump. If you have a fuel pressure tester, you can start the car - run it - turn it off and see if the pressure drops. If it does - you have a fuel pressure leak. Tank seal, fuel pressure regulator, fuel filter, fuel rail, even a bad fuel injector can cause a pressure drop. You should check all the connectors and seals for tight fit.

65Z01

When you turn the key on the pump only runs for about 2sec so a weak pump may not fully prime the fuel rail.

When I turn my key on the rail primes to a over 40psi.

Since it holds well after you shut off the engine I doubt you have a leak.

radwebster

changing fuel pump is very easy...i just did it with very limited tools...took less than an hour :cheers:

Darkness

Its easy to do it but beware so that you dont leak any gas on your paint or else...

CentralCoaster

Does that noise from the passenger side of the car, happen mostly on cold startups? It's not the fuel pump (its in the tank).

I'm pretty sure it's actually chatter in the lines. Similar to water-hammer that might happen in your house's water pipes if you turn the faucet on or off to quick.

It's a very common problem, but I have yet to see anyone that knew what caused it. There's supposed to be some sort of dampener in the fuel line to prevent this, so maybe that failed somehow. Or maybe it's caused from air being in the lines on startup, from leaky injectors of a bad fuel pump check valve.

Let us know if the new pump cures the noise though. :yesnod:

Slalom4me

I would add

Step #4a - DISCONNECT THE BATTERY

But that's just me



[Modified by Slalom4me, 11:17 AM 6/3/2003]