Idle Surge

[91boostfedGSX]

First Off I Have A 1991 Eclipse Gsx. To Give You A Lil Background On The Car Its Basically Stock, Tubular Pacesetter Manifold, 2.5" Exhaust, Big 16g Runnin About 15 Psi. When The Car Is Cold(it Does This Any Time Hot Or Cold, But Only Starts High When Cold) You Can Start The Car And It Will Idle In Between 2300-3000 Rpm. As The Car Warms Up The Rpm Will Gradually Lower, At Times It Will Idle Really Well. But Most Of The Time When It Gets Down To Around 1100 Rpm It Starts Surging Really Bad...ive Cleaned The Throttle Body, No Boost Leaks, Cleaned The Idle Air Control Valve, Tps, Anyone Have Any Suggestions On How To Stop This Problem??

 

[habitatguy187]

What's your idle when the car is completely warmed up (like summertime) You might want to check your biss screw.

 

[Dserge]

First Off I Have A 1991 Eclipse Gsx. To Give You A Lil Background On The Car Its Basically Stock, Tubular Pacesetter Manifold, 2.5" Exhaust, Big 16g Runnin About 15 Psi. When The Car Is Cold(it Does This Any Time Hot Or Cold, But Only Starts High When Cold) You Can Start The Car And It Will Idle In Between 2300-3000 Rpm. As The Car Warms Up The Rpm Will Gradually Lower, At Times It Will Idle Really Well. But Most Of The Time When It Gets Down To Around 1100 Rpm It Starts Surging Really Bad...ive Cleaned The Throttle Body, No Boost Leaks, Cleaned The Idle Air Control Valve, Tps, Anyone Have Any Suggestions On How To Stop This Problem??

I have the same problem. On cold starts my car will idle surge up and down up and down until warm. This leads me to believe my FIAV in my throttle body is messed up.. Not sure how to go about getting it fixed but I think that is what the problem is.

After the car is fully warmed up the FIAV is not used anymore thus fixing the problem.
The only thing I know of is to block it off.

I would like to actually fix mine though..

 

[hubz91talontsi]

You need to replace your TB. In the first gens the TPS and ISC go bad. Will cause the car to pretty much fall on its face at idle may even die like mine =X. Just replace it with a 91-94 TB or buy the new sensors they are like $50 each.

 

[Dsmj89]

First try ordering a new biss screw with cap, if that doesn't solve the problem then order both new isc and fiav sensors. One step at a time.

 

[hubz91talontsi]

It's not the bliss screw how would that make the rpm's surge. Do you have an safc? It will prove it to you. When your car will almost die the rpms will go higher then normal and your TPS will raise even if your foot isn't on the pedal.

 

[habitatguy187]

I have the same problem. On cold starts my car will idle surge up and down up and down until warm. This leads me to believe my FIAV in my throttle body is messed up.. Not sure how to go about getting it fixed but I think that is what the problem is.

After the car is fully warmed up the FIAV is not used anymore thus fixing the problem.
The only thing I know of is to block it off.

I would like to actually fix mine though..

Did you block the coolant lines to your TB? If so it will cause this problem.

 

[domestic hater]

I've had the same problem with my 91 and it was the tps.I got one at the salvage yard for 5$ just test it before you get it

 

[Dsmj89]

It's not the bliss screw how would that make the rpm's surge

I didn't say it would cause the surge, but it does in fact play a role in high idle, it happened to my 91 tsi awd, i just never got to fixing it, i just kept adjusting the screw whenever it would fall out of place.

 

[92tsiawdguy]

Sounds like the fiav. you can get a block off plate from jmf.

 

[jrohner]

It's not the bliss screw how would that make the rpm's surge. Do you have an safc? It will prove it to you. When your car will almost die the rpms will go higher then normal and your TPS will raise even if your foot isn't on the pedal.

This makes no sense at all. The tps value doesn't change unless you move the throttle (unless the tps is shot and the value is jumping around); the BISS does not move the throttle plate, it's an air passage that basically goes around the throttle plate and the screw opens and closes that pathway.


Idle surge is caused from something making the idle speed too fast -- FIAV stuck (or coolant not circulating), or BISS adjusted out too much. When RPM's are up and the throttle is shot, the ECU cuts fuel for deceleration to save fuel and that's what causes the idle to go up/down/up/down.

You don't actually need a working ISC to have a good idle either. I've only messed with 1 DSM that even has a working ISC -- they are ALWAYS shot. If the FIAV thing works correctly, the idle will be fairly consistent without a working ISC (other than headlights, AC, Fans, rear defroster, etc slowing it a little when they are on).

 

[Srt4RacerDave]

My idle surge in my 1g was caused by a bad idle air control valve. Replaced it after having pretty bad idle surge for a month, and it fixed the problem. I know this link helped me when I had surge problems -

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


Read that article completely and it should help you fix your idle surge with a lot more ease and understanding. Goodluck!

 

[91boostfedGSX]

I Appreciate Everyone's Information..sad To Say My Gsx Will Be Out Of Commision For A While...im Not Sure Why But Doing An Interstate Run Last Night And Got To 150mph And Let Off....blew The Headgasket I Beleive...i Got White Smoke Puffin Out Of The Dip Stick Tube And Its Missing Really Bad...like Its Only Runnnin On 3 Cylinders

 

[97GSTAUTO]

I thought awd dsm's are speed limited at 140mph.

 

[habitatguy187]

I thought awd dsm's are speed limited at 140mph.

I believe only the 2nd gens had a speed governer. I might be wrong though.

 

[91boostfedGSX]

I Let Off At 147.... Anyone Know Where I Can Get A Dual Wastegated Manifold

 

[92tsiawdguy]

why do you need a dual wg mani? i run an sc6152sp turbo on a 38mm wastegate with no creap.

 

[91boostfedGSX]

gonna be using a gt4088r...

 

[92tsiawdguy]

at what psi

 

[91boostfedGSX]

when all is said and done ill be roung 40psi