Have you checked for vacuum leaks?

 

When you removed the IAC was the pintle fully extended? If so you might try replacing the IAC. Usually if it is fully extended like that you either have a bad IAC or there is a vacuum leak and the PCM commands the IAC to shut in an effort to compensate for the vacuum leak.

Jimmy

 

I say even if a sensor tests ok replace it anyway I had an TPS that worked great half the time the other half not.

Also when cold ok but under hard working conditions not

At a certain age replace all your sensors you are better off

Always save the old sensors as backup label and date them.

 

The pintle was fully extended, but isn't it suppose to be because of the spring it has?

I've visually checked my hoses and they all look good. Is there another way I can check them?

 

The IAC is a stepper motor, does not contain a spring. If you shut the truck off and remove the IAC, it should be retracted a small amount.

 

Funny my IAC had a spring in it??

 

Yea my IAC fully extended to the tip as far as it goes, I pushed it down gently to clean out the carbon Inside with carb cleaner. Pulled out some small bits but didn't feel any difference, still idles rough and misfires every now and again. I guess I'll try changing it out if it's not suppose to be that way, see how it runs after

 

I learned the hard way you are not supposed to push or pull on the pintle shaft of the IAC. Try a new one and drive the truck a few miles to let the PCM adjust to the new IAC. I had a problem with my truck a couple months ago where it would not idle on a cold start and would try to bog down and die when coasting up to a stop. I installed the old OEM IAC that came with my V8 throttle body and it has been idling fine ever since.

Jimmy

 

If you were having an injector problem, you would have gotten a P0201 and P0203 injector codes. That would also cause misfire codes too. Are you loosing coolant? Because if you are, you could have a head gasket problem. The most likely problem and I know you will not believe me, is the cylinder head. If you have more than 75k on the engine. Replace both cylinder heads, and if you do replace the heads. Don't remove the distributer, Because you will loose your sync timing.

 

I don't have any 200 codes only 300, 301, 303, and 305 have showed up. Started with and now have pendings on 300, and 301. There's 150k on the engine but I have not lost any coolant and engine has not over heated at all.