Expert: Van - 7/27/2005

Question
i have an s10 blazer that runs fine when cold but after about thirty minutes the car stalls out. the temp is normal. if i let the car sit and drive it the same distance at night, i have no problem with it stalling. i have replaced the egr valve, the crankshaft sensor and the fuel filter. do you have any idea what could be causing this problem.TCC? coil, ignition etc...

Answer
Hello Randy,
When the vehicle is cold, the ECM does not use sensor values to adjust fuel injection, timing, etc. In stead, default values are used.
So throttle position sensor, oxygen sensor, etc are all possibilities.
Fuel starvation is also a possibility if the gas tank vent is plugged, and a vacuum forms inside the tank. Try loosening the cap to isolate that one.
First thing to check would be for spark. If there is spark when it dies, then fuel, or a large vacuum leak is what I would check for.
If there is no spark, then ECM, or ignition module may be temperature caused problem.

The night difference may just be that it is cooler then.

Van

Van