I have noticed the last couple of months now with the cold weather my 96 4.3 Blazer is having trouble idling in the mornings on occasion. It doesn't do it all the time but about 25% of the time I will start it and it will not attempt to idle it just stalls. When it does this I have to rev it a couple of times then gradually let off the gas til it will stay idling around 500 RPMs. Any one have any suggestions as to what may be causing the problem. I just did a complete tune up last year (plugs, wires, distributed, cap & rotor)

 

I would recommend that you remove and thoroughly clean the throttle body, specifically the IAC (idle air control) valve and passage.

 

Its been awhile sense I posted about this and finally was able to try some of the suggestions. I cleaned the TB and had no luck. The problem seems to have been getting worst. Now when starting, close to 50+% of the time, the engine cranks once and then acts like it wants to stop unless pump the gas. The starter just went out the other day. I have replaced it and still have the same symptoms. I didnt clean the IAC as I am unsure where it is located. I was also wondering if it may be a good idea to replace the fuel filter and or run some injector cleaner threw it? Any additional help is much appreciated. Thanks