high idle problem

[LOWBOOST91]

Ok, so I have this high idle problem I have been chasing. I think I have narrowed it down to two things. The FIAV or the coolant temp sensor. ( which im still not sure the coolant temp sensor would cause that.) Im gonna hook it up to link tonight to see exactly what all my sensors are putting out tonight.

It only does it once it gets hot. My ISC is new, My throttle cable is not to tight, and I tried spraying starter fluid to find a vacuum leak and didnt come up with any thing.

Any advice would be greatly appreciated.

I have searched, mostly what I found was the throttle cable and the isc being bad.

 

[92AWDHX40]

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


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

 

[Rock2610d]

How high is the idle?

Do you have air conditioning? If not is your ac button on?

To help it would be nice to know what it idles at cold and hot.

 

[LOWBOOST91]

Cold it starts at 800 (with the BISS all the way in) it gradually works its way to 1000, once it warms up it goes to 1900 and some time surges, its just really all over the place. once it warms up thats when its worse.

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


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

I have seen the second one from a google search but the first one i have never seen, Thank you, I printed it off, should be very helpful

 

[92AWDHX40]

You are welcome.

 

[Kod]

Yea the FIAV is either bad or you got a boost leak that isn't sucking in enough of the fluid to kick the idle up has happen to me before, and always test the ISC, even new parts can still be bad, I had 3 bad ISC given to me from the box before I got a good one..

Only thinking FIAV or boost leak because if your BISS is bottomed out then it has to be one of those too (be careful not to get it stuck)

Obviously idle should be 750 + / - but not 800 cold and then sky rocket when hot with BISS all the way in with a working ISC motor.

Cold everything is tight, hot everything expands

 

[962ndgen]

I agree with kod, either your ISC is bad or you have a small boost leak. Have you tested your system for a boost leak? Its good to keep up on leak tests I do one once every 6 months or so.

 

[nicks1999spy]

I had same problem with mine turned out to be the IAC idle air control
Located on the throttle body it happen on my 98 gst and my gtv6 3g

 

[LOWBOOST91]

I think I have narrowed down to the fiav. The plunger moves in and out like its supposed on the isc. My readings on link are good from the O2 sensor and the coolant temp sensor.

As far as boost leaks go. My fmic is crap on this car. Its a scrap set up basically. So I plan on ordering a new one and having it installed before I start driving the car again.

My throttle body has a crack on it where the bolt goes in (if your facing the throttle body on the top right) just cosmetic damage.

So that being said, My plan is to order a new(used) throttle body off ebay, perform the fiav block off, install a new fmic with new couplers and all. Then boost leak test it. My car will be down for a little while, due to funds but I have my trusty neon for my dd so shouldnt be a problem