Greetings everyone on previous threads I mentioned that on cold starts my truck would stumble as it was trying to lower the "cold" higher rpm's as the engine was warming up. Well this started happeneing even after the truck was warmed. On both occasions I would hear this hissing noise ( found out it was the IAC letting in more air ) the the engine would recover. When I took off during this episode (engine warmed already) the truck would stumble for a second then recover. This weekend I installed my Pacesetter shorty headers and Accel Performance coil and did other little work that needed doing ( cleaned and reoiled my 3" round style K&N air filter , installed new front O2 sensor, etc. ). When I was done the battery had went down due to the doors being open and the radio playing. I had enough jiuce to get it to turn over but it would never fully "catch". After applying the jumper cables it still wouldn'e unless I pressed the gas pedal while it was turning over however the minute I let off it would die. I called a buddy who's a mechanic and he stated the IAC valve needed cleaning or replacing. I had a new IAC laying around so I replaced it and the truck ran fine. After a couple of days of driving the truck started to stumble again during warm up but not nearly as bad and only lasting for a few seconds whereas before with the other one it would do this for about a minute or 2. Should I remove the new IAC and clean the port that it sits in? And if so how do you do this?

 

hello anyone out there i need help

 

the first thing i would do is reset the pcm by removing neg battery cable and either turning on headlights for 30 sec or turning key to start for 30 sec. either way it drains the power from stored memory. then reconnect battery and start it up and let it figure itself out. see how it does.

since it worked ok a couple for days ago the iac port is probably ok.

 

to clean the iac well, simply remove it and spray some carb cleaner or wd40 into the well. stick your finger in there and swab it out until it feels smooth and clean and you finger comes back out clean. check/clean the iac pintle as well but do NOT push or pull or twist on the iac pintle or you'll break it.

i've fought an IAC problem before where i had cold idle surging to 2000 rpm and then warm stalling, and it turned out to be the TPS and not the IAC, so I don't know how to tell, so now i just replace one and if that doesn't fix it replace the other. keep the 'good' old parts for the next time.

 

How many miles are on the engine?

 

Basically remove the two screws that hold it on to the back of the TB. Pull it straight out but do not compress the valve. Look it over and make sure it hasn't become gummed up. If so carefully clean it with some TB cleaner. Also spray the TB cleaner in the valve housing and allow it to run out.( Put a clean rag on the manifold under the valve housing to catch the draining TB cleaner.) After it drains out then carefully wipe out the housing with a clean lint free cloth. ( If you have access to compressed air you could spray that inside the valve housing to blowout any debris stuck to the sides and to facilitate drying it out.) Reasemble in reverse of the order you took it out. Make sure that you didn't ruin the gasket on the valve mating surface. Install the screws and tighten them up. (I don't know if there is a torque spec for the screws but snug them tight.) It should be good to go. Now that I have said all this please realize that this is a little tough to do leaning over your truck. What might be better is to remove the whole TB and clean the whole thing top to bottom including the IAC which would be easier to remove. Your choice as to which method you use.

 

140k on the odometer

 

The IAC is brand new I had an extra one lying around that I never used. I stuck my finger in the hole prior to installing new one and there was nothing on my finger. Prior to replacing it I did spray some carb and choke cleaner on top where the pintle seats while the engine was running. And with the lift and the removal of the stock crank fan blade ( i installed a flex-a-lite dual electric fan) I just stand in the engine compartment on the suspension bar that runs across the front.

 

Hopefully it's not the TPS because that is relatively new as well.

 

I'll try resetting the PCM. I've heard about turning the key but not the one about turning on the headlights.