HELP! Chevy S-10 stopped running~~no fuel

89 4 cylinder S-10 Pick Up

I poured a little fuel into the throttle body and it starts. Figured fuel pump. Check voltage to pump and got 8.3. Against my better intuition I replaced the pump (figuring I had voltage so the pump must be bad). With the new fuel pump instructions came this note: "a loss of oil pressure or a defective oil pressure switch will cause the pump to be inoperative." No mention of this in the Haynes repair manual that I have.

I put 12 volts to the old pump and it hummed like it supposed to. Grrrr.

Apparently the problem is the lower voltage, or..........

Anyone have any experience with this? Any help would be greatly appreciated.

Frank

Reply to
F.H.
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"" wrote: > 89 4 cylinder S-10 Pick Up > > I poured a little fuel into the throttle body and it starts. > Figured > fuel pump. Check voltage to pump and got 8.3. Against my > better > intuition I replaced the pump (figuring I had voltage so the > pump must > be bad). With the new fuel pump instructions came this note: > "a loss of > oil pressure or a defective oil pressure switch will cause the > pump to > be inoperative." No mention of this in the Haynes repair > manual that I > have. > > I put 12 volts to the old pump and it hummed like it supposed > to. Grrrr. > > Apparently the problem is the lower voltage, or.......... > > Anyone have any experience with this? Any help would be > greatly > appreciated. > > Frank

Try changing the O2 sensor and mapp sensor. I have it on good info that it worked on a ?91 with the same symptoms. Runs good now.

Reply to
rob

Thanks. Will try. Noticed yesterday that a fuse ECMB 10-A is blown and won't take a new one without blowing it. Any idea what fuse that is for?

Reply to
F.H.

Nether of which have a damn thing to do with the fuel pump.

EngineControlModule ie the computer that runs the fuel and ignition system. Can sometimes happen with a bad oil pressure sender, also wiring can get near the exhaust and get cooked is another possibility.

Whitelightning

Reply to
Whitelightning

According to the manual the two sensors mentioned *can* cause the ECM to cut the voltage to the pump. But after reflection I decided not to start replacing parts to quickly. You are closer I am sure. The 10 amp fuse for the ECM was blown and it blows new ones. Any guess on that? Cooked wire? I jury rigged a fuel drop thingy so I can start it and it will idle for awhile. When I do that, the oil pressure is strong.

Reply to
F.H.

Since that blown fuse doesn't keep the ECM from working I'm wondering if it's the wire that the ECM uses to control the fuel pump relay. Perhaps the relay itself has a short in it?

Reply to
Ashton Crusher

Hmmm, good logic. I take a closer look (again).

If and when (my source is on vacation so I've got busy with other projects) I get it analyzed via computer I will post the results. These are handy things to file away. The Ford newsgroup has saved me quite a few dollars with my 4.6 T-Bird and I, in turn have been able to help others.

Reply to
F.H.

Get a ohm meter and check the wire feed ciruit tfrom ECM to pump for grounds/shorts with it disconnected at the tank. Another though is that the pump is getting ready to fail and is drawing too much current for system fuse and causing problem to. If you have access to a amp meter, you might check the current draw on pumps when it is hot wired.

Reply to
SnoMan

It blows fuses with the pump disconnected. The old pump hums pretty good when hooked to 12 volts. With a voltmeter I get (key on) voltage of 8.3 give or take at the outlet that connects to the pump.

Reply to
F.H.

OK genius's, new pump installed and hot wired (to get the 12 volts). Now I have fuel pressure at the throttle body but it still won't run. Here's the clincher, if I squirt fuel down the throat of the throttle body it trys to run but if I just crank....., no luck. No way to check fuel pressure but if I losses the inlet line it squirts all over the place. Any ideas?

Reply to
F.H.

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