Idle high

[punka44]

Hi. I have Eclipse 1991 GS NT and I've problems with idle speed, when motor is cold. When I start up (I don't move with car) rpm goes to 1500 rpm (good) and slow down to 750. But If I move with a car, the iddle speed goes up to 2400 rpm and then oscilates between 1500 - 2200 rpm. When I'm running it's OK, but if stay for stoplight and put my gear to neutral, than it makes the same oscilation for a moment and than goes down to 750 rpm. When the motor heats up, everything OK. It's terrible and nobody know's where's the problem. Thank's everybody for help.
Peter.

 

[teme]

Measured the ics pins ? First do that so we know if it's broken or not...


and btw, you should really try use the search, damn lot of questions of idle that can help you.

 

[beaty-k_87]

checked your PCV valve? thats why mine idled high.

 

[punka44]

Thank's for your ideas. I'll check my PCV valve tomorrow.
Teme what are "ics pins" please? Thanks.

 

[teme]

Idle Speed Control motor pins I mean, check this website

http://dmtalon.v8eaters.com/ISC.html

there is instructions how to test it.

 

[punka44]

Hi guys. I checked PCV and ISC motor and they works. Do you have any more ideas? Thanks.

 

[SpeedFreak03]

Sounds like your FIAV is shot (Fast Idle Air Valve): http://www.vallotton.com/fiavblockoff.asp

 

[H.A.R.T 4G63DSM]

i have the same problem as you.... I was just about to post it up also. Thx for doing it before me. Yeah and I have been doing research on them and its most likely our problem.

 

[punka44]

Than's SpeedFreak03. I'll check it with my mechanic a I will replay what we'll find. Oh, you'r alright H.A.R.T.4G63DSM. But we will solve this problem together on this forum! I believe.

 

[H.A.R.T 4G63DSM]

hahaha yeah we gotta fix this problem... its getting annoying to drive....

 

[punka44]

Thank's for help everybody. I would like to ask if it's possible to replace only the FIAV or I have to change whole TB? Or it's possible to repair the FIAV?

 

[punka44]

Hi, I solve the problem with iddle surge in my car. I tried to change my ECU and this was the problem. Now with new ECU the car run perfect and also when the motor is cold, the rpm slowly goes down, no wr wr at all. Bye.

 

[Pro3racer]

How much did that cost you? I may need to swap ecu's also, since i have tryed everything myself, and i still have idle surge.

 

[t0taleclipse]

i got you all beat.

mine started as a simple - couldn't hold idle and die at a stop then it was surging at warm up and now its all those things plus from low rpm to around 2500 rpm it feels like its missing but clears up at high rpms.

got and answer for me.

tested:

TPS - good
ISC - coils good but shaft only comes out about 1/8" maybe 1/4" (is this normal?)
COIL PACK - good
PLUGS -replace
WIRES- replaced

I know a vacuum leak would cause the idle problem but the stumbling and poor gas mileage?

any ideas for me???????


92 laser rs N/T and only 66,000 original miles

 

[Pro3racer]

EGR valve, that would explain the bad gas mileage for sure, take it off, clean it, check to see if it still works, then put a new gasket on it(make your own), and see if that helps. Then post back, i have done the same as you, yet i still have idle surge, ha. So we might be in the same boat. BTW, where is the coil pack, is it where the plug wires go into, sorry for my stupidness, but its late and cold here, so i don't want to go outside, i just need a very basic idea of where it is.

 

[t0taleclipse]

ya the coil pack is where the wire plug into. Cold there, it' like 17 degrees here and working on my car sucks out there.

 

[t0taleclipse]

EGR valve, hoses and solenoid all good and in spec. What else is there?

 

[Pro3racer]

FIAV, sucks, but that is your last thing. Try taking you TB apart, clean it out very good, dry it very very good, and see if that helps.

 

[t0taleclipse]

Bad FIAV, would that make the car have loss of power and kinda miss? I had the TB off a few months ago and the gasket was bad but i put it on anyway. Maybe there is a leak. Maybe i Got a stuck injector. I'll have to keep testing to see.

 

[Pro3racer]

Yes please, we have the same problem, so maybe we can work together on this one. I'm selling this car, time for a tsi, the only idle problems with this, is that it idles low, no surge(that was fixed).

 

[punka44]

My new ECU cost $300, but I'm from Europe and here it's not cheap to be DSM men.

 

[Pro3racer]

Was that new or used?

 

[t0taleclipse]

I'll pass on the new ECU for now. How can you check to to if the ECU is bad?

 

[Carlson61588]

Get your nose as close to your ECU as possible. If it smells like rotten meat or rotten fish its most likly bad. I had the problem on my old Eclipse. Does anyone know what the 2in x 2in black Denso box underneather the stock radio. It has about 10-15 wires the go into it and i dont know wtf it is. If anyone can help that would be great.

-Carlson
www.CrUnderground.com

 

[punka44]

Hi, my ECU was used from the same motor from Galant. Eclipse and Galant have the same motors 4G63. If ECU is good or bad? I have only one advice what did I too. I borrowed another ECU from a guy who is dealer for used DSM autoparts in my country. Get off my old ECU and tried this new one. I had it for a weak in my car to check if has no side effects. Everyhig was OK, no idle surge, no side effects. Now I have this ECU for a month and the car runs great.