Idle still surging.

Ok Guys I replaced IAC motor and the idle is better but still not right. No vac leaks of any kinded tested the whole system with carb cleaner and everything is sealed up tight. Should I be looking at the TPS?

 

[Muskrat]

Do you have a logger?

TPS should be at about 10% and move through the whole range up to 100% when the pedal is pressed (car doesn't have to be running, just have the key in the ON position).

If that's not it it's possible your FIAV is leaking.

 

Dont mean to be a noob but what is the FIAV?

 

[Muskrat]

Fast Idle Air Valve.

It's in the lower portion of the throttle body. It allows more air into the engine when it's cold. Coolant flows into it, and as it heats up it closes. That's why when you start the car it'll idle a bit higher until it warms up.

A lot of people just block it off. I think there are details on VFAQ.

 

Thanx for the info I will check out the VFAQ.

 

OK looked on VFAQ and the thread was no longer there. But will wont I have troble starting the car in the winter?

 

[Muskrat]

I can't comment from personal experience (mine's still hooked up, and I just got the car on the road anyway), but the FIAV isn't about starting but getting oil to flow. So if you do decide to block it off you'll probably have to rev the engine manually for a minute or so when it's cold, to insure proper lubrication.

 

Yea that may be a pain. I will check to see if I can find one. But I have to change the whole TB right.

 

Check your ECU. Mine was going bad and causing idle surge. I replaced the FIAV first also thinking it was that. If you have a friend with an ECU to borrow that always helps too.

 

[rgeier11]

Almost guarantee the ECU. It's happened to me on two different cars as well as a couple of my buddies.

 

[464/2K]

Try bleeding the coolant system, one of the most over looked things that cause surge, especially after opening it up to replace the FIAV.

 

That might make sense considering my radiator is leaking.. LOL Have not replaced it yet. An there is no overflow bucket.( Need to get one) Trying to get the tranny fix.. /ubbthreads/images/graemlins/smile.gif