My truck will start right up, but unless I rev the engine it dies right out (as if someone hit a kill switch). IfI start my truck and keep reving the engine I can drive (slipping it into neutral at stoplights and signs) and after 10-15 minutes it will then idle on its own at around 700 RPM. Sometimes I can start the truck giving it a lot of gas and bring the RPMs up to 2000-2500 and then the engine will settle out and idle fine (doesn't always work though). It's not showing any codes. The truck has about 120K mikes and I've recently changed the plugs and wires, but that did not correct or have anyeffect on the problem. It reminds me of an automatic choke that's sticking, but this is a fuel injected engine, so what's the deal? Is there a sensor somewhere that may not throw a code, but still giving a false signal?...would a faultymass airflow sensor cause this??

 

I'd check for leaking vacuum lines.

Could also be a TPS or IAC issue.

 

My guess, yes guess, would be the IAC (Idle Air Control) valve. You can try tapping, I said tapping, the IAC with a screwdriver hab=ndle to see if it helps any. It should look similiar to the picture below.

 

Thanks! Ichanged out the IAC value last night. Very simple, and so far so good. Starts with just the turn of the key and idles smoothly at around 700 RPM.