I have a 96 Blazer 4.3L with auto tranny, it has been having hesitation when accelerating and rpm would drop slightly on occasion (200-300rpm) when driving at highway speeds. It always seems to be worse if the engine has been idling for more than a few minutes. The only time it wouldn't do this is when the air temp dropped to 10-15 degrees or lower then no issues at all. I was driving yesterday and the vehicle completely died, engine shut off, no power to guages or radio. Started pulling off the road and and after only a few seconds of no power all guages and the radio came back on and the engine restarted it self!

Took it to the shop and he can't find anything wrong. No engine codes nor did it have any issues when he drove it. My mechanic and are are both totally stumped. The only thing he thinks it could possibly be is the computer module but without any codes to work on the only other option is to replace it and see what happens. He doesn't like to randomly start replacing parts unless he sees no other option so i thought I'd see if anyone here could help first.

Just a little history. engine has 209k miles. plugs, wires, cap and rotor replaced 25,000 ago. fuel pump,tank, filter, and lines replace 10k miles ago. Battery and battery cables replaced about 1 month ago.

 

Could be the electrical part of the ignition switch.
Mine would shut off while driving then turn back on a sec later. Weird things happen when they start to fail.

 

I say it's a ignition switch failure but that's just a good guess!!! Do a search on ignition switch failure.......all the info u need is there

 

Well???? No update? Wonder why nobody else chimes in???