fuel pump?

Topic: fuel pump? (Read 1742 times) previous topic - next topic

fuel pump?

November 19, 2008, 10:24:56 PM

What seems to be the idea for fuel pump replacement?
1988 5.0 110k miles, all stock, for now...

Today the car turned over easily but would not fire. I checked fuses and the switch in the trunk but everything seemed fine. Looked under the hood and all seemed fine. Slammed the hood and it occurred to me to listen for the fuel pump. I turned the key and heard nada. I cycled the switch a couple of times and nothing. I tried one last time and I heard it, I turned the key to start and it fired right up.

Previously the car has stalled/almost stalled when making hard u-turn, regardless of fuel level.

OK internet doctors, what is the diagnosis?

Thanks in advance.

fuel pump?

Reply #1 – November 19, 2008, 10:47:13 PM

Could be the fuel pump relay or the fuel pump its self.

Relay is easier and cheaper and dosn't require the dropping of the tank.

fuel pump?

Reply #2 – November 20, 2008, 07:19:01 PM

Started ok today. I suppose I'll just wait until it is like 45 degrees and raining before I get serious about this, like usual.

fuel pump?

Reply #3 – November 21, 2008, 01:11:43 AM

start engine
hold brake
put car in gear
cut wheel hard left or right
put foot on brake reall hard
press gas slightly to about 2k rpm

does it feel like ts gonna stall then?

fuel pump?

Reply #4 – November 21, 2008, 01:27:41 AM

Might as well swap out the relay first -- it's a $5 part. Mine used to stick on and drain the battery. Snapped in the new relay and smooth sailing ever since.

fuel pump?

Reply #5 – November 21, 2008, 09:24:29 AM

Yep,check the relay.It's in the trunk under the right side of the package shelf.Should be green,mounted up high all by it's little self.

fuel pump?

Reply #6 – November 21, 2008, 02:53:42 PM

Quote from: 88fiveo;243962

I turned the key and heard nada. I cycled the switch a couple of times and nothing. I tried one last time and I heard it, I turned the key to start and it fired right up.

possible ignition switch issue

fuel pump?

Reply #7 – November 21, 2008, 09:26:44 PM

well,,, if you think its ok just to shot gun the problem, then go for it.

fuel pump?

Reply #8 – November 23, 2008, 07:58:10 PM

I'm sure the ignition switch is going as well. A couple of months ago I was cruising near the speed limit and looked at the speedo (as I was approaching the local SO), and I had no digital speed or guages or blinkers. I jiggled the keys and the dash lit back up. It has been fine since then though and I drive this car about 10k a year so it gets a lot of use.

I will try the brake/turn wheel tomorrow, if it starts...

Thanks, and no I'm not into the shotgun approach, no funds for that.

fuel pump?

Reply #9 – November 24, 2008, 10:53:13 PM

OK, so it started today, but I had to hit the gas a couple of times to keep it from stalling. Once the fast idle switched over to normal idle I tried the brake/turn wheel to lock/rev it up trick. Both left and right behaved fine, no stall. I tried it again after work and when I got home, no stalling. What did that prove? I have no clue.

Also, I looked for the fuel pump relay, but there is a cardboard looking "cover" that is covering the underside of the package tray. It looks like it is held on by those push pins. I had to get to mu daughters soccor game (they won 1-0) so I didn;t mess with it today.

Thanks for the help so far.

fuel pump?

Reply #10 – November 25, 2008, 02:10:06 AM

Quote from: 88fiveo;244648

What did that prove? I have no clue.

Thanks for the help so far.

Based on your original symptom, It "proves out" several things in one bundled troubleshooting step eliminating all of them. When you are in a u-turn situation, obviously your foot isnt deep into the gas, you add load to the engine by putting demand on the power steering, also any form of a binding smog pump might show up here also. If you had come back and said it kinda wanted to stall based on the test you did, most of us would have had you remove your serpentine belt and repeat the step. Next, with a warm motor , manually spin pullys and see which one seems to be binding.

since this did not happen,

its time to trottle back and look at actual fuel presure.

Your fuel pump relay is on the pass side rear trunk area just on the far side right of the pass side trunk hinge behind the linder / cover. The relay will have a green top, wiring diagrams in my diy link as well.

one more thing can be done in advance, get your fuel presure reading.
next, pull codes,, all of which are in my diy link.

I hope this helps, these are quick things you can do that do not take much time just like the first test you did.

fuel pump?

Reply #11 – November 25, 2008, 07:22:28 PM

Gotcha, I don't have access to a fuel presure guage that will read that high. I have an old and I mean 1970's guage that goes to 12 pounds. Not the 50 or so I would need for a "high" reading with today's cars. It did fine again today. I'm thinking of replacing the fuel filter just for fun. I realize it would not cause the "no fuel pump sound" non-start situation I have right now. It is always a cheap/good idea.

Going away for the holiday and won't be around to futz with the car for a few days. Thanks for your ideas.

fuel pump?

Reply #12 – November 27, 2008, 11:03:30 PM

I was told that the fuel pump has a check ball and that if that fails to hold after shutdown, the line fuel drains back down to the fuel tank by siphon effect. Anyway, that appears to be my problem. To help avoid this and a lot of engine cranking, I turn the key to "on" and wait a few seconds and then repeat that --and wait 10 seconds--of course leaving the key in "on" position. Then I crank it. It appears to eliminate most of this problem. Otherwise, I have no other fuel issues--the car runs well otherwise--could this be your problem? The only cure is to replace the pump.

fuel pump?

Reply #13 – November 28, 2008, 11:15:02 AM

the stock bosch pump has a round / flat disc like object on the end as though it might be the check valve your talking about.

Not hearing the pump run is problem one.

I would double check with two people.

one guy turns the key

the other guy holds the relay and listens / feels for the relay click.

if it clicks,, and no pump noise then yep its time for a pump.

Ths does not mean the relay is good, it just means the relay clicked.

If you turn the key forward and you hear a click but no pump, beat on the bottom of the fuel tank with whatever dead center. If the pump then comes on, your definatly looking at a pump.

Dont put this off any longer, better determine what is failing either relay or pump and get it fixed. A bad pump will come and go and one day just leave you sitting.

My recent purchase of a 20th anny gave me no warning and left me sitting in rush hour afternoon traffic in wash dc. I was simply merging to go home into 66west traffic and the car stopped.

fuel pump?

Reply #14 – November 28, 2008, 08:35:57 PM

My ignition switch caused me the same grief.