Really strange/high idle

[videogamemaster]

Alright so I have this 1991 Eclipse GSX and it has a really weird idle that I can't figure out. It sometimes idles at 1000 but most the time it idles like its revving from 1500-2000 (can be seen in video). I tried the BISS screw and it is tightened all the way down. And truthfully I dont know crap about the SAFC-II so maybe that could fix it.

My mods are as follows:
16G Turbo
Injen Intake
FMIC
3" Turboback exhaust
550cc Injectors
255 Walbro Fuel Pump
HKS SSQV BOV
AFPR
SAFC-II

I also noticed that I am missing a belt which I believe powers the ac/heater cus neither work (its the lower belt that runs on two pulleys). I also noticed when driving that my exhaust temps on the gauge ar usually around 1000-1200 is this normal or high?

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[habitatguy187]

Search for "Idle Surge"

 

[videogamemaster]

Search for "Idle Surge"

Alright i tried high idle and it didn't help much so Ill try that

 

[JFatch1890]

Yeah i got the same problem right now so don't worry.Look up idle surge on vfaq.com.It will be under (intake) i think.It gives you a little bit of info on it.Its a pain in the A$$.I got mine to stop that damn bouncing now it just idles at like 2 grand and then i mess with the biss and it will lower and idle perfect then i shut the car off and start it back up and then it goes back to 2 grand .But vfaq will give you pretty much most of the info.Good luck

 

[GSXSixteenG]

Vacumn leak. Check intake gasket or throttle body gasket

 

[habitatguy187]

A vacuum leak won't cause this.

 

[videogamemaster]

So after some searching would my BOV being vented cause this?

 

[habitatguy187]

So after some searching would my BOV being vented cause this?

, vented BOV's can cause all sorts of stuff. Recirculated it and tell us what happens.

 

[Lofty]

So after some searching would my BOV being vented cause this?

Possibly, I'd check your ISC, it's really easy.

DmTaLoN's Idle Speed Control Test/Fix Page!

Just recirc that BOV, Home Depot racing style.

Or if you like venting, get a Gm MAF and a MAFT

 

[videogamemaster]

Possibly, I'd check your ISC, it's really easy.

DmTaLoN's Idle Speed Control Test/Fix Page!

Just recirc that BOV, Home Depot racing style.

Or if you like venting, get a Gm MAF and a MAFT

went to home depot and nothing would fit on the ssqv so imma have to order that adapter fitting

 

[GSXSixteenG]

Well my Honda use to do this until I replaced the intake manifold gasket. Which I thought was considered a vacuum leak.

 

[GSXtacy724]

you are right, it very well could be a bad intake mani or TB gasket. I'd check your Idle Speed Control sensor like Lofty mentioned. A bad TPS (Throttle Position Sensor) would do this too. How long after venting your BOV did this start?

 

[dsmfa9nutter]

It's a vacuum leak. Check all the hose barbs on the intake for hoses attached to them/capped off. The other belt doesn't drive the "heater", that's powered by electricity. When you turn on the heater, do you hear a fan turn on in your dash? If not, you've either blown a fuse or the blower fan is dead and needs to be replaced. If it turns on but no heat comes out (after the car is warmed up), you either have a blockage in the heater core or your lines aren't connected.

 

[JFatch1890]

Yeah i got pissed off cause someone spliced what i think is my isc and it didn't have a plug and ripped the wire off and and it stopped that idle from going up and down I just wanted the car to idle somewhat to work on it .I know that wasn't probably a good move but i didn't care at that moment.I got the manual in front of me and it says the first step would be to check for vacuum leaks.So go head and start simple and work your way up the ladder.

 

[habitatguy187]

A vacuum leak can cause idle to surge, but not from 1500-2000rpms. All a vacuum leak does is lets in unmetered air, therefore your ecu doesn't add the fuel to compensate for it, so you run lean, get misfires, and have slight idle variations. If anything a vacuum leak will lower the idle from the normal operating range due to the misfires. There's something else going on with an idle like that.

Lofty seems to be on track here, check your ISC. Then go through the idle surge list on vfaq.

 

[habitatguy187]

Also the o-ring behind the BISS screw might be trashed, letting air in and raising idle. Cheap replacement go to Talon, Laser, Eclipse 1G Info DSM and check it out.

 

[94Jettameowpsst]

Do you have crusie control? If so check that, can you close the butterfly in the TB manually from the TB? If so i'd say you have a corroded cable
I just had the same issue

 

[talonDSMerr]

A bad FIAV can also cause idle surge. Usually that's the problem when there's idle surge at startup that goes away once the car is warm.

 

[habitatguy187]

A bad FIAV can also cause idle surge. Usually that's the problem when there's idle surge at startup that goes away once the car is warm.

Or if you have the tb coolant lines blocked off it will do the same thing until the car is warmed up.