The vehicle in question is a year 2000 chevy blazer automatic six cylinder motor with 125,000 miles on the odometer. The check engine light recently came on indicating a problem with the camshaft positioning sensor. The motor acted like it was running on five cylinders; very rough with decreased power. I changed out the sensor along with a new rotor and distributor cap. The motor started up right off and seemed to run very smooth for several weeks. But than after running for awhile with the motor warmed up, if it was shut off it wouldn't start again until everything had cooled off. This happened repeatedly until I changed out the camshaft positioning sensor again, thinking maybe it went bad again or I had gotten a defective sensor. However it never did show the check engine light again as in the beginning of all this. With another new sensor the motor started up okay when cold and when hot. This lasted all of two days and now its back to starting okay when cold and not when hot. Still no check engine light coming on. When cranking over while hot the motor shutters and jumps as if not all cylinders are working. I've checked all the connections I can find looking for corrosion or looseness. What could be getting hot and keeping the motor from starting. This is very frustrating and the vehicle has become unreliable for my wife to use.

 

Have you checked the timing chain? It might be off a smidge from the heat and/or wear.

 

Also check the distributor for excessive play. The drive gear on the bottom of the distributor is prone to wear.

peace

 

check your ignition control module voltage when engine is cold and when the problem starts when it hot to see the voltage and resistance readings and differences, all the while keeping the harness connected to the icm.

 

you're starter may need to be replaced in the near future. My friend has this problem and his starter is going bad