Chevy S10 Pickup 4.3L 1991 2wd truck

[fatdaddy62]

I bought my son this truck. We are a bit frustrated as the truck stalls and quits running as if the computer shuts it down. I put new plugs, wires, rotor button, dist cap. I pulled the control module and had it tested. Adv Auto said it was good so I added dieletric grease and reinstalled the part. I had a chrysler van that had a MAP sensor go bad that behaved this same way. I have not seen check engine light come on. I replaced FF since it idles rough as well and has since we purchased the truck. Now I am getting killed by car insurance for a 16 yr old boy and am shotgunning the truck to see if I can keep my cost down. I need to verify that the check engine light comes on for a moment when the key is turned on. I am tempted to replace the MAP sensor and possibly the FPump (I checked it when it died on me going about 45 MPH after dring 15 minutes, it was delivering the fuel to the TBI. I don't have the pressure guage to test this but it seems to me the computer shuts it down after it hits a consistent operating temperature. After it sits for an Hour or so I can start it and drive a few miles. HELP I used to work at a service station and now the world of computers and sensors has left me without knowledge based strategies. Oh, I did listen for the Fuel pump and I can here it in the gas tank when the key is turned to the on position.

[drdd]

have you cleaned the throttle body (w/ TB cleaner)?

have you cleaned the EGR sensor ? (Exhaust Gas Recirculation)

have you cleaned the IAC sensor? (Intake Air Control)

PCV and air filter ??



QUOTE=fatdaddy62]I bought my son this truck. We are a bit frustrated






as the truck stalls and quits running as if the computer shuts it down. I put new plugs, wires, rotor button, dist cap. I pulled the control module and had it tested. Adv Auto said it was good so I added dieletric grease and reinstalled the part. I had a chrysler van that had a MAP sensor go bad that behaved this same way. I have not seen check engine light come on. I replaced FF since it idles rough as well and has since we purchased the truck. Now I am getting killed by car insurance for a 16 yr old boy and am shotgunning the truck to see if I can keep my cost down. I need to verify that the check engine light comes on for a moment when the key is turned on. I am tempted to replace the MAP sensor and possibly the FPump (I checked it when it died on me going about 45 MPH after dring 15 minutes, it was delivering the fuel to the TBI. I don't have the pressure guage to test this but it seems to me the computer shuts it down after it hits a consistent operating temperature. After it sits for an Hour or so I can start it and drive a few miles. HELP I used to work at a service station and now the world of computers and sensors has left me without knowledge based strategies. Oh, I did listen for the Fuel pump and I can here it in the gas tank when the key is turned to the on position.[/quote]

[BlazerLT]

How about checking the timing with the timing wire dsconnected from the PCM under the dash.

Also, ever replaced the fuel filter?

Could be a fuel pump dying out too.

[fatdaddy62]

I will likely try the fuel pump. The way it shut down right in the middle of driving really made it feel as though the computer shut it down. That's why I thought it was the map sensor like my crysler did. This may sound stupid but I have never cleaned an EGR or IAC sensor. How do I do that without damaging the parts?

[Allbert]

Maybe check for contaminated fuel or a partially blocked inlet screen in the tank.

[fatdaddy62]

I just measured and checked the ignition coil and pick-up coil both measured properly to the manual. I have removed the EGR valve and it is black on the inside but it will create a vaccum when I push on the diaphram and release. There did not appear to be any thing in-operable with it. Any suggestions. I am going to ohm meter the map sensor next.

[BlazerLT]

Originally Posted by fatdaddy62

I just measured and checked the ignition coil and pick-up coil both measured properly to the manual. I have removed the EGR valve and it is black on the inside but it will create a vaccum when I push on the diaphram and release. There did not appear to be any thing in-operable with it. Any suggestions. I am going to ohm meter the map sensor next.

Read my last post..

[fatdaddy62]

BlazerLT Thanks. I don't have a timing light. I loaned it out and it never returned to me. Bother or neighbor I can't remember. After I got back to the truck again I cleaned the EGR and the other things. there has been no check engine light either. I am now half way through the Fuel Pump change. I cannot believe how difficult they make getting to the hoses to remove them. I am on the ground and using a jack to lower and support the fuel tank I did this on a Lumina APV I had and it was much easier. Oh well, probably should get back to it. Any suggestions where I could get a Cheap timing light? I priced a few and Advance did not even stock one.

[fatdaddy62]

Good news with all the work I am doing I am getting to know this truck real good. I also cleaned the PCV valve, checked air filter and replaced the fuel filter that I mentioned earlier I believe. I did notice the vaccum lines were a bit fragile but I don't hear any hissing or see any holes. Back to the fuel pump, I think I am beginning to procrastinate. Later. Thanks for all your help.

[fatdaddy62]

Finished the marathon put it all back and now have no fire not from the coil. When I measured it today it cheked exactly as the book said. I am really confused. No check engine light still but I did verify that it came on when you first crank the car. I measure the pickup coil and it too was what the book stated it should be. I have an unfriendly ghost in my truck. I was able to verify the fuel pump ran when I turned the key but it did not seem to flood the throttle body that I could see. Help !!!! My neighbor did have a timing light so If I ever get fire Ican check the timing.

[BlazerLT]

No spark at all?

Ignition module or the coil is shot.

[fatdaddy62]

I cannot access at work. I took the coil out last night and measured as it as the manual said to and bolted to the car I thought it measured bad. So I removed it and double chcked myself and it measures good. I measured it in circuit with the key on and there was power to the connectorthen I trace the line over top the ignition module and measured 12V in on that line with the key on. I pulled the ignition module out last night and was sending it to Adv, Auto to test it again. My book said to measure the TACH terminal with the key on. it said it was 'Taped back near the distributor. I removed the other module connector w key on and had voltage at one pin, (less than 10 I believe) and all others were low. I measured the coil wire and got about 8k I believe it was. I am tight on cash right now but if you think it is the module I will replace it. What if AA tests it and they say it is good. What would I look at next? Could the coil give sporatic readings and fool me from my ohm meter? is there something else I should check. Coolant Temp sensor was suggested by one trouble shoot guide.

[fatdaddy62]

I forgot to mention that I measured the pickup coil again and it seemed ok. Hopefully the test at AA today will show the module from the distributor is bad and then I will be done with it. Study it and let me know if you have other ideas.

[fatdaddy62]

Test concluded that the module is definitely good. I am thinking the ECM any opinions?

[fatdaddy62]

I replaced the throttle position sensor and IAC and now the stalling while mid driving have ended. Fix one thing find another. I also had a plugged cat converter and drilled a hole to get some power back as it was a slow pig. Thankfully the Lord let me get there and poster from another spot on this site was right-on. that closes this one.