A what if question..

[gn85]

I have just recently noticed that my IAC numbers were in the 80s or so at idle. I am replacing my IAC as I have new one, I will set it correctly and will reset my TPS.

Two questions..

1) what is the chip telling the IAC to do when it's not idling?? Driving down the road.

2) With my IAC and min air screw being improperly adjusted what effects, if any, could that have on performance of my car?

Thanks for the theories and facts...

 

[TurboJim]

Originally posted by gn85
I have just recently noticed that my IAC numbers were in the 80s or so at idle. I am replacing my IAC as I have new one, I will set it correctly and will reset my TPS.

Thats most likely due to the TB being oily/coked. If you set the min air (theoretically you only need to set once) if the IAC counts go out of whack, its because there isnt enough air entering the engine pre-adjustment. Be it, dirty throttle nody, wrong PCV valve, whatever

Two questions..

1) what is the chip telling the IAC to do when it's not idling?? Driving down the road.

Dont remember the exact value, but it is programmed in the chip. I think its called throttle follower. The IAC will open an amount in anticipation of you letting off the gas, to catch the stall.

2) With my IAC and min air screw being improperly adjusted what effects, if any, could that have on performance of my car?

Well, if the engine is anticipating a certain amount of air pre-IAC, and you dont have that air, problems such as extended crank times, start-stall, start-hiccup, decel stall, tip in hesitation, stuff like that can result.

Thanks for the theories and facts...

See if anyone else has anything to add, but that is avout it in a nutshell.

 

[gn85]

Thanks Jim..

That sounds about right... a few of the things my car has done, but haven't been that bad. My tip-in acceleration has never been GREAT so there's a possibility. Start up cranking is occasionally long, although some times if fires up when I touch the key. As far as decel stall, I've never really had that. Very rarely it may stall on a hard stop. It will act like it holds its breath.... thinks about it.... then runs.

As for the original problem, I may have misset it a long time ago then never bothered with it again. Just something I noticed recently looking through some t-link files.

Thanks Jim for answering my question...

Anybody else have something to add??