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1994 Chevy s10 4.3 TBI won’t start when warm

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Old Mar 30, 2020 | 1:50 AM
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Default 1994 Chevy s10 4.3 TBI won’t start when warm

My truck starts up fine no problem while cold, but as soon as it gets warm and I try to start it again it just cracks over and over and usually takes me around 5-10 minutes to get it started again. It only does this if I’m let’s say running errands and I’m in and out, but it’d it’s site for a while then it will start back up fine

Here’s what I have changed:
distributor
cap and rotor
iac
rebuilt TBI
O2
fuel pump

Last edited by charrisps6; Mar 30, 2020 at 1:56 AM.
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Old Mar 30, 2020 | 5:11 PM
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Could be a myriad of issues, but fall into 3 categories-intermittent fuel delivery, a failing fuel system elec mod control, or ignition elec...does the truck smoke any for a bit when ya need to do those warm starts?-that may be a sign that a/some/or all spider injectors are leaking by, or a control module isnt shutting down the injector/s, allowing gas to dump after shutoff, momentarily...which basically floods the truck upon restart...also, a momentary lack of signal TO the injectors when it is warm will also cause a hard start......or, u could possibly have an issue of getting fuel pressure...as I stated, this is only a few possible cause, aint sayin' any are yours.....Me, i'd start simple-remove a spark plug when truck wont start and check for spark-that will eliminate or confirm 1/3 of the map-ignition elec...yeah, means carryin necc tools around and doin it in a parkin lot or some some other really inconvenient spot or replicating the issue while at home and in yer garage........this is a good example of why mechanics have these expensive live data OBD tools-to eliminate throwing parts, prayin' one will finally solve the issue....I feel your pain when ya just dont know where to start/look, but sometime, just paying a Prof mech for a diagnosis is money well spent.....just spit balling here.....good luck and please post back when issue is found....

Last edited by hogbiker; Mar 30, 2020 at 5:14 PM.
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Old Mar 30, 2020 | 8:53 PM
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Fuel pressure was good to go, and I tested the coolant temp sensor with a volt meter and it was good as well, I replaced the map sensor and nothing changed, but I did run into something strange, I had an old ignition coil laying around and I piped it in and it ran an engine light and ran terrible, but it fired right up every time, so I put the old one back on and it seems to be cranking pretty consistent, could this mean I reset mine or needs a new one?
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Old Mar 30, 2020 | 10:06 PM
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Heat is the enemy of failing electrical components. Things like coils and ICM's may be fine at cold start, but become intermittent once up to operating temps.
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Old Mar 31, 2020 | 12:31 AM
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I’ll keep y’all updated on the situation, doing more driving tomorrow to see if the crank stays consistent, if so you think I should put in a new coil?
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Old Mar 31, 2020 | 2:46 AM
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Sounds like you narrow'd down the 3 categories to 1-elec. IF when you stated "it ran an engine light and ran terrible, did you mean the "check engine" dash indicator lit up and the temporary coil was used while u were experiencing the "wont start warm" condition?....if so, plug in an OBDII tool and what the code/s is/are.....yes, please keep us posted
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Old Mar 31, 2020 | 8:48 AM
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Yes the engine check light was on, now when I say I swapped it out with a coil sitting around I just plug it up and didn’t bolt it in, did it have to be bolted in (grounded)?
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Old Mar 31, 2020 | 9:17 AM
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not to my knowledge...now OBDII time, to see what's throw'n the ck engine light
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Old Mar 31, 2020 | 10:06 AM
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Unfortunately mine is OBD 1 and right now I have the original one in there and it doesn’t have a light, that was just one I tried for a lap around the block and it threw a light but it was cranking like a champ, no hesitation at all, so I took it out and put the original one back in
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Old Mar 31, 2020 | 1:22 PM
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brain cramp-my mistake, OBD I, being a '94...glad to hear issue resolved
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