1992 blazer will not restart hot.

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HotWheelsBurban

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I was unable to check it out because it happened at the supermarket. I’m hoping I have Saturday free to run down the issue. Does anyone know how the coolant sensor could be a factor in this?
I know that the coolant temperature sensor in the intake manifold under the thermostat housing, is the one that talks to the ECM and controls the fuel mixture. Don't see how that would affect starting, but I will be the first one to admit I don't know everything! That's why I have all 41,000+ of y'all to ask!
 

AuroraGirl

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Not without the engine running crappy all the time.
if it has a vacuum leak I could see a non working ECT making it work till its warm then on restart it doesnt properly prime up and then its a *****

But thats just a thoery, looking for codes, and looking at the essentials will get you farther than guessing
 

east302

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How would the water temp sensor keep it from hot starting as mentioned in a earlier post? I replaced it with a new one when I rebuilt the engine 2 years ago.
The computer uses the ECT sensor (versus the temp gauge sender on the head) in calculating air/fuel mixture. If it thinks that it’s extremely cold then it will call for too much fuel and flood the engine.

Here’s a diagnostic table from a 94 manual which goes into a little more detail. Holding the gas down while cranking is a workaround if it is flooded as it temporarily stops injector flow.

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someotherguy

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In case there's any doubt, a failed CTS/CTS circuit can absolutely prevent starting as it will fuel-foul the plugs. I've experienced it. It's not just something they put in the book to take up pages. ;)

Now, your 2 year old CTS is probably not to blame.. but you should follow the diagnostic procedures available until the usual suspects are eliminated.

Richard
 

Schurkey

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The usual failure of CTS is that they tell the computer it's really cold--like Forty Below Zero. IF (big IF) the CTS was to blame, the warmer the engine got, the worse it would run.

I have the sense that this engine runs fine--it just won't start when hot.

Smells like ignition problems from here.

I'd be checking for spark and fuel spray when cranked, when the engine is hot enough to not start.
 

wb292

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Ok. It looks like it a fuel problem. I got my wife to crank it today and the injectors barely dribbled anything out. Extremely small amount of fuel. I have changed the ECS and the FP relay. Along with the oil pressure sender. Same issue after sitting about 30 min it fires back up and runs great. Still gets 21MPG and has plenty of power when accelerating. Driving to work in the morning it’s cooler and it doesn’t do it. Only in the afternoon running the AC after the 70 mile drive home. Should I be thinking the ECM?
 

alpinecrick

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Pump is new and gives a solid 13 psi while running that never changes. Is this the coolant temp sensor by the thermostat? I believe that's new too but that doesn't mean its good these days.
First guess is ICM (Ignition Control Module). They are well known to crack, and lose contact when hot when they expand, and begin working again when cool and contract. It's located in the distributor.
 
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