1994 Chevy S-10 Starting

Tiny
1985SR5
  • MEMBER
  • 1994 CHEVROLET S-10
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 204,000 MILES
I have a 94 chevy s-10 V6 4.3 TBI, the engine turns over but does not start. I have done some test. The whole fuel injection system is not being powered. I know I have a good fuel pump. I ran a power wire directly to it, to test it. But the injecters still do not turn on. I know it gets spark, I had it running when I sprayed fuel down the throttle body. I had this problem 6 months ago, but it stopped and just started again. Any Ideas?
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Monday, June 9th, 2008 AT 1:13 PM

17 Replies

Tiny
RASMATAZ
  • MEMBER
I know i have a good fuel pump.

The only sure way to tell is to actually perform a fuel pressure test with gauge.

Ignition switch at run position you should have power at the red and white wires to the injectors. If not Check ECMl fuse 10amp. If you have power on these wires and the injectors are not pulsing-it coming from the computer ground driver of the injectors. See below


http://www.2carpros.com/forum/automotive_pictures/12900_driver_3.jpg

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Monday, June 9th, 2008 AT 2:20 PM
Tiny
1985SR5
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Ok I tested the ECM wires at the fuse block and they tested positive(+) now the wires at the PCM I have nothing. My fuel pump is good I replaced it 6 months ago thinking it was the problem, but it didnt help. Than one day it deside to start. Now when I turn the key to the on position I dont hear the fuel pump priming the system. Something is shuting off the whole fuel injection system. And I have no clue ive done a bunch of test. I have new relays in for the fuel pump. Ive tried a new PCM ive looked at all the wiring and I just cant figure it out Please Help:-(
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Monday, June 9th, 2008 AT 8:12 PM
Tiny
RASMATAZ
  • MEMBER
Now when I turn the key to the on position I dont hear the fuel pump priming the system. You got 2secs to hear the fuel pump before the fuel pump relay de-energizes the power to the fuel pump-

Have helper put key to run and you go check for power at the gray wire at the fuel pump connector.
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Monday, June 9th, 2008 AT 8:38 PM
Tiny
1985SR5
  • MEMBER
Alright I did that I have no power at the fuel pump and I tested the reelay its good but its not swiching on and off with the key. When I run power right to the fule pump I turns on but the injecters still do come on. I also just tested the ignition switch ever thing test good there.
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Tuesday, June 10th, 2008 AT 3:57 PM
Tiny
RASMATAZ
  • MEMBER
The computer energizes the fuel pump relay.
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Tuesday, June 10th, 2008 AT 5:21 PM
Tiny
1985SR5
  • MEMBER
Well I dont think its the computer I have tryed 2 diff computers with the same ID# and nothing changes im guess its just a wireing problem some where just need to find it. Do you have the whole wireing diagram to the computer so I no what im working with are there any sensors that would tell the computer to not turn on the injecters and fuel pump? Today I examined the wire harness for the computer. No broken or corroded wires im going through all the wires under the dash right now.
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Tuesday, June 10th, 2008 AT 9:29 PM
Tiny
RASMATAZ
  • MEMBER
There's no camshaft sensor for this model-some manufacturers uses the camshaft sensor to synchronize the injectors-

Inspect and test the distributor pick-up coil resistances in the distributor and check the wiring all the way to the computer for short and open.

I believe the computer is using the signal from the distributor pick up as the ignition reference to energize the injectors.


http://www.2carpros.com/forum/automotive_pictures/12900_d1_2.jpg




http://www.2carpros.com/forum/automotive_pictures/12900_d2_2.jpg

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Tuesday, June 10th, 2008 AT 11:29 PM
Tiny
1985SR5
  • MEMBER
I cant read the resolution so small...


http://www.2carpros.com/forum/automotive_pictures/199646_s10_1.jpg



If you want since this site only let you put low pixle pics you can e-mail me them if you like. 1985sr5@gmail.com
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Wednesday, June 11th, 2008 AT 8:16 AM
Tiny
RASMATAZ
  • MEMBER


http://www.2carpros.com/forum/automotive_pictures/12900_inj_1.jpg

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Wednesday, June 11th, 2008 AT 8:25 AM
Tiny
1985SR5
  • MEMBER
Alright I have tested all the wire you wanted me to. I have also had me ignition control module tested and it tested good. So I than moved on the the fuel pressure switch I put a new one in. The orange wire I had like 9. Something, the distibutor ref hi (ppl/wht) tested at.131, and the distibutor ref lo (blk/red) tested at.014
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Wednesday, June 11th, 2008 AT 1:46 PM
Tiny
1985SR5
  • MEMBER
I still havent found the prob. If anyone else has any ideas please let me no.
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Saturday, June 14th, 2008 AT 11:51 AM
Tiny
HELLCARRIER67
  • MEMBER
Im having this same problem. Did anyone find the solution, if solet me know hellcarrier67@yahoo. Com
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Monday, February 23rd, 2009 AT 4:52 PM
Tiny
NED662
  • MEMBER
We are having the same problem with our pickup as well. It turns over but no sound from pump. The pump is fine. Anyway we are unable to locate the fuel pump relay switch. Any information on locating this so we can test it would be greatly appreciated.
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Thursday, June 25th, 2009 AT 11:40 AM
Tiny
TEAM39763
  • MEMBER
We replaced the fuel pump relay, but still no sound form the fuel pump. We checked and it isn't pumping any fuel through the lines either. Before we changed the relay, the pump would try to turn on right after you let off the key while cranking, but only then and for a split second. Any ideas?
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Sunday, November 8th, 2009 AT 1:39 PM
Tiny
TEAM39763
  • MEMBER
We supplied 12v to our fuel pump to make sure it was pumping and the truck still wouldn't start. We checked to make sure we had power/signal at the injectors and we did. But the injectors still weren't spraying. So I decided to clean the injectors with B12(chemtool) and blow them out with compressed air. I didn't pay attention, but the orings expanded in the B12 so the injectors couldn't build up any pressure. All the gas came spilling out from the injector housing. I have now ordered a gasket kit from autozone(about 6bucks). I'm hoping that improves the situation. I'll post up with an update.
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Tuesday, November 17th, 2009 AT 8:30 PM
Tiny
TEAM39763
  • MEMBER
I replaced the gaskets and o-rings, but the injectors still didn't fire. I was told that I may have done some damage to them when I cleaned them, but I'm not sure yet. I am sure I'm getting fuel pressure, but I'm not sure whey the injectors don't fire. I read that the injectors always have 12v, it's the ground that makes them fire, so I'm gonna go try playing with that a little and see what it does. I'm very close to just pulling the motor out and dropping in a carbureted 350. This is really frustrating my whole family.
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Sunday, November 22nd, 2009 AT 1:33 AM
Tiny
TEAM39763
  • MEMBER
Can someone atleast give me an idea of what the problem could have been? We decided to go carbureted since TBI seems to have outsmarted us and everyone we know.
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Thursday, November 26th, 2009 AT 6:43 PM

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