Maybe it will run maybe it won't

I have a '99 Chevy Blazer. For the last 7 years I go out crank it and you knows the rest of the story, it run and I am on my way. Lately however it has be hard to crank on a hot day or when it does crank it runs for a while and then it stalls in the street, and then will not crank at all until it is cold. I have had to have it towed home 3 times. I have replaced the fuel pump, fuel filter, fuel relay, control module, battery, alternator, and the EGR value but it still stalls. The GM Dealer says the injectors are bad. Yeah right! They never removed the air intake plenum to check the injectors. I have learned to never trust the dealer. Any ideas anyone?

Try checking the resistance of the crankshaft position sensor when it’s cold. Then when the engine stalls, check the resistance again. If it’s out of spec, the crankshaft position sensor is failing when it gets hot.


A friend of mine had a honda that did the same thing he found on a hot day he could take his gas cap off and he could hear the pressure release and then put it back on and the car would run fine. The gas cap was not venting correctly you may try that at least its a free test. Also his car would run like a top in cold weather the colder the better it seemed like. Good luck.

Define “Crank” Some people use that term to mean the starter is moving the engine and others use the same turn to mean the engine starts.

By crank I mean it is running.

The engine cranks (turns over), but doesn’t start, when the engine is hot, right? That I understand.
What I don’t understand, is, “…it is hard to crank…”. How is it hard? What does that mean?

If the truck has been sitting and is cold it will crank up and run fine as though nothing is wrong. But as soon as the engine warms up it will stall out and will not start again until it is cold again. Once it is cold it runs again.

Either replace the crankshaft position sensor; or, have someone check its resistance (ohm value) when the engine gets hot and stalls.