1992 c1500 5.7l hard start when warm

littlemlittle · Jan 17, 2020

I'll drive it to the store to get groceries, shut it off run in the store for about 30 minutes. Come out and it does this.

Starter doesnt engage and then I shut the key off and do it again it struggles.

I replaced the starter and it still does it after its warm.

Rebuilt 5.7l

I have replaced the coolant temp sensor (front of intake)

Maybe the map or ignition control module?

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PlayingWithTBI · Jan 17, 2020

What's your base timing with the EST wire disconnected? It should be set to zero* with a timing light.

littlemlittle · Jan 17, 2020

I made sure it was 0 when I started it up, after the break in and everything. Made sure it was reading correctly and then plugged it back in. (Shutting truck off first)

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PlayingWithTBI · Jan 17, 2020

Did you calibrate your TBI controls?

TBI tuning-website - Tuning the TBI.pdf

I'm asking so you don't have to start throwing parts at it. How about putting a scanner (not a code reader) on it and see what it looks like when it starts OK then, when it doesn't? I have seen and heard of the ICM going out especially, if it's not a quality brand like AC Delco or Delphi.

littlemlittle · Jan 17, 2020

I have not calibrated the tbi controls I will look into that. I also dont have a scanner, so I wont be able to look at that.

My engine light isnt on but I might jump the connection to see if it reads anything, guess it wouldn't hurt?

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littlemlittle · Jan 17, 2020

I went to check the timing again.. dist bolt was a little loose. Also found out maybe my fuel regulator is leaking?

Tell me what you think. I know it's not supposed to be back there..

I also plan on doing some spark plug wire organizing this weekend..

Also sorry for the poor quality cell phone video.

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littlemlittle · Jan 19, 2020

Well, i rebuilt the fuel regulator, put a new gasket on the fuel line plate? (Underneath regulator) and put a new icm in and it runs much better.

I guess it was dumping too much fuel in with that leak. It has a much better throttle response.

Thanks for the help.

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1992 c1500 5.7l hard start when warm

littlemlittle

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PlayingWithTBI

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