1992 Chevy S-10

1992 CHEVROLET S-10

90,000 MILES • 6 CYL • 2WD • MANUAL

PARMAN440

MEMBER
8 POSTS
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My s10 has a 2.8 v6 throttle body.
It is backfiruing and sometimes stalling.
I have put new cap and rotor, plugs/wires, EGR valve and solenoid, cat, O2 sensor, Maf sensor, coil, fuel pump, fuel filter.
I had inadvertantly tried to start the truck while I had the jumper in to check trouble codes.
What is the liklihood of me damaging the ecm by doing so?
Is there a way for me to test the ecm or do I have to have it check at a dealer or repair shop?
I do not want to spend another 100.00 on an ecm just to find out that is not the problem.

Oct 1, 2010 at 5:21 PM

RASMATAZ

CAR REPAIR CONTRIBUTOR
75,992 POSTS

Check the ignition timing and fuel pressure

Oct 1, 2010 at 6:34 PM

PARMAN440

MEMBER
8 POSTS

I replaced the ignition control module and the fuel pressure is good.

Oct 1, 2010 at 6:48 PM

RASMATAZ

CAR REPAIR CONTRIBUTOR
75,992 POSTS

What was the fuel pressure ? You sure the wires are not leaking, and also the firing order correct-could also be a lean or rich mixture

Oct 1, 2010 at 6:54 PM

PARMAN440

MEMBER
8 POSTS

I am not sure what the pressure was.
The fleet guy at work checked it and said it was okay.
I had a code that said it was running rich before I put the O2 sensor in.
So you don't think I could have done anything to the ECM by trying to start it with the jumper key in place to check for trouble codes

Oct 1, 2010 at 7:03 PM

RASMATAZ

CAR REPAIR CONTRIBUTOR
75,992 POSTS

Probable causes of an engine running rich are as follows:

1.Excessive fuel pressure can be cause by restricted fuel return line or defective fuel pressure regulator.
2.Defective Oxygen Sensors.
3.Leaking injectors and fuel pressure regulator.
4.Coolant temperature sensor out of calibration.
5.Restricted air intake system.

Oct 2, 2010 at 5:48 AM

PARMAN440

MEMBER
8 POSTS

New fuel pump, oxygen sensor was replaced.
That seemed to take care of the truck running rich.
That trouble code never came back.
My main question is this.
Could I have done something to the
ECM by trying to start it with the trouble code jumper key in place?

Oct 2, 2010 at 6:27 AM

RASMATAZ

CAR REPAIR CONTRIBUTOR
75,992 POSTS

It won't do any harm to the PCM -

Oct 2, 2010 at 10:26 AM

PARMAN440

MEMBER
8 POSTS

So I can rule that out?
Someone said something about the tps (throttle position sensor.
I was gonna pull the temp sensor and check that.
Another forum said that there is a coolant temp switch as well. How do I check that or is that not realevant.
The parts guy at O'reillys also said something about a smog pump. Could that be a problem?

Oct 2, 2010 at 10:58 AM

RASMATAZ

CAR REPAIR CONTRIBUTOR
75,992 POSTS

Could be the air injection pump diverter valve when it backfires during deceleration also check the check valve-

Oct 2, 2010 at 5:22 PM

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