1G Idle surge when cold, gone when warmed up

[dsmcoder]

I have idle surge problem on my 1g gsx when my car is cold. When its warmed up the surging stops most of the time, might do it once in awhile. I replaced the isc a few months ago, but I haven't checked it yet.

Anyone have an ideal on what could be wrong?

 

[1990AWD]

Sounds like the FIAV isn't working right. I don't think you can replace it at all, but you can block it off.

 

[92nolatist]

Wow....I just wrote up this big thing on another thread about this exact issue.
Look at Post #9:
http://www.dsmtuners.com/forums/newbie-forum/392429-94-eclipse-na-questions.html

 

[dsmcoder]

Is there any way to test the FIAV? What would the side effects be if I blocked it? Where I live the temperature can get as low as -50 degrees without windshield. As a matter of fact we were the coldest town in the lower 48 states a few weeks ago -46 really cold, I have the newspaper article if anyone wants to see it. I'm not sure if temp makes a difference but I though I should tell you guys just in case it does.

 

[92nolatist]

There is no way to test it. Side effects however, may include stalling while driving when the car is cold (like in between shifts or coming to a stop). Thats pretty much the only thing I can think of.

You just have to let your car warm up for a bit before you go driving it; although you should be doing that anyway. Also you could block it off and still keep the coolant going through the TB so it wont freeze up on you. You just need to apply some silicone to the bypass plate on the side without the gasket, so coolant wont leak out.

 

[dsmcoder]

I have an automatic, would the car still stall?

Watch this video, this is not my car but it idles exactly like this one until it warms up.

YouTube - Weird Idle on my 1991 Mitsubishi Eclipse GSX

 

[92nolatist]

It might stall, but I dont have an A/T so I wouldnt know. I would say go ahead and bypass your FIAV then adjust your BISS and be done with it. If the car wants to stall when cold, bump up your idle a little bit.