Does anyone remember who did this, or where this thread is? I've tried searching for where I read on here that someone modified their TB to eliminate the annoying IAC valve issues. There were those who suggested it wasn't a great idea, but whoever did it said it worked great. I want to look it over again and see if it is something I might want to attempt. I'm tired of mine never functioning correctly at start up. I've replaced it and it still does the same crap.

 

I believe it was Indy. He cranked the screw on the tb if I remember right to idle higher at idle.

 

Sounds like you have an issue with the electrical harness that should be diagnosed.

 

Thanks guys for the quick response. I'll check the wiring harness and make sure it's clean and making good contact. If that doesn't help, I'm going to try adjusting the screw on the TB. My truck runs good, but on a cold start, I hate the surging and sucking sounds it makes. I also hate how long it takes for the PCM to relearn the fuel adaptives after the it has been reset, like when the battery has been disconnected, or when a new program gets downloaded into it. It seems like the truck runs very different evry time I drive it for a few hundred miles. That's how long it seems to take for the PCM to settle down.

 

Ron,

Don't mess with that screw! It'll cause you all kinds of headaches. For me, it messes with the TPS and causes all kinds of issues on accel and throttling. Also, I've destroyed 2 IAC's trying to adjust it the way Marty suggested.

2 suggestions:

Try unplugging the IAC, turn on engine, let idle, accept CEL, kill engine and then plug the IAC in and fire it up again. The idle will start really high and then calm down. Clear the code if it doesn't go away.

if that doesn't work, Buy a new IAC. They go bad frequently.

 

if a new IAC doesn't help, then replace the TPS. their signals are all in-bred together in the pcm. i f**ed around with my IAC for the longest time. a new one would sometimes fix the problem for 6 months, or, until the next season of cold weather, then it would surge again. replaced TPS (again) and it fixed it.

+1 on don't turn that screw.

 

Thank you guys for your input. I have decided to learn from your experiences, so I will take your advice and leave that screw alone. I will fix it the correct way, and not just eliminate it. Too bad it couldn't be that simple, and permanent.