Ive got a 94 1500 that cranks fine however it idles good for about 3 seconds at around 700 rpm then the rpms drop. most times the engine will stay running going thru this cycle until it dies. However after if i can keep it running and it reaches 190 degrees and the t stat opens it idles fine. I have replaced water temp sensor, idle air motor, tps, map sensor and O2 sensor. I also installed a new fuel pump with 20psi and 40gph about 2 weeks before this started and a new fuel filter and it worked fine. I can give it gas and it runs fine. Just wont idle when cold. I can unplug the map sensor and it will idle fine. What am I missing. There is nothing else that I know of. Thanks for the help in advance.

 

my 93 had similar symptoms and needed a new distributor. But only idled rough for less than a minute, then normal after that.

 

i also replaced the ignition module and the coil in the distributor

 

The issue may be caused by a problem with the idle air control valve.

 

Yea I replaced that. No luck