FIAV good or bad?

[2GbGSXbeast]

How can you tell if your Fast Idle Air Valve is working or not? I've been having extreme idle issues and have already replaced all gaskets on intake side of engine including FI O-rings, checked/tested IAC, TPS. Nothing has helped. It will idle around 1500 to warm up the engine like normal, but once it's warm the idle creeps up between 2k-3k. Sometimes if I tap the gas it will begin surging and then go back to 2k-3k. Any ideas. Thank you.

 

[boost97gst]

You might have got a false positive, if you will, when you tested the ISC coils. Those are usually the cause of idle surge. Almost all the time.

 

[92AWDHX40]

Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge)


http://www.dsmtuners.com/forums/articles-engine-fuel/191137-how-fix-your-idle-surge-problem.html

read through these it may help.

 

[2GbGSXbeast]

ty very much

 

[DKJson2112]

I had idle surge, and my car even bucked after idling for a period of time. Mine was idling low, so I loosened the BISS. It sounds like you need to tighten yours a turn or two. I'm not too sure what I'm talking about though. The rpms on my car would sag the come back up while idling, but I fixed that by gapping the spark plugs.

 

[2GbGSXbeast]

I have a BBK tb only has a butterfly adjustment, which I checked and can not be the problem. I have an OEM IAC installed which again tested within spec. I also have an aftermarket one I have also tried that tested out of spec and it didn't change anything. I even wasted $100 on a new TPS. I installed a new coolant temp sensor today I guess we'll see if that helps.