hello all,
I'm a new member to the forum, my name is mike, im an older carbureted engine nut and dont know alot about the newer computer controled engines. I just purchased a 92 chevy 3/4 ton pickup with a 5.7litre tbi engine. I have a problem with idle on the truck and need some help. when you start the truck when it is cold it idles for a little while but when it warms up it idles down and dies. it will stay runnin if you remove a vacumm line like the pcv valve, most of the time. the engine is a hihg mileage engine but runs fine and doesnt smoke. except for a rich fuel smoke and smell... if anyone can help with this please let me know.....mike

 

This sounds like a fuel flow problem. . . I had a problem with my 97 SFI Vortec a few years back. Apparently the over use of fuel additives had dissolved my fuel regulator causing a rough idle that sometimes resulted in the engine dying. This can cause engine misfiring which can be detected specifically by a diagnostics computer from your local auto store. You should also check your induction system to make sure you're getting good airflow (poor airflow causes the engine to run rich and burn excess fuel)