91 Eclipse idle problems

[MVOVER]

Hi,

My friend has a 91 Eclipse GS-T that is having an odd idle problem. When it's idling it can't seem to find where it wants to idle; it goes up down up down, not as bad as it used to be but sometimes it goes from ~800 to ~1200 but mostly it plays between high hundreds and a grand. It was worse before and it got a bit bettter after new plugs went it. It's got something like 120K on the clock, so I figured it's about time things start breaking.

I was going to suggest he put new spark plug wires in as well since the plugs cleared it up a bit, but I'd rather figure out what it is then just replace stuff until we find it (since I'll be working on it). I thought it might be the distributer, but then wouldn't it do it all the time? Would the O2 sensor cause this?

Any opinons are appreciated. Thanks,

MVOVER

[EK 2.0]

Your problem is most likely the BISS screw...which stands for Base Idle Set Secrew...its located right at the Throttle Body...there was supposed to be a lilttle rubber o-ring, but over time that weakens and you lose it, the screw either loosens, or backs all the way out cause your idle surge...the other problem is the ISC...The Idle Speed Control Module....I will give you a couple of links to check and you can go from there...let me know how it turns out...

Arif.

BISS Screw

ISC Module

Idle Surge

[GTS Jeff]

while ure at it, its never a bad idea to replace old wires and whatnot.

[Daxin]

Originally posted by MVOVER
Hi,

I thought it might be the distributer, but then wouldn't it do it all the time?MVOVER

Eclipse's don't have a distributer, it has a coil pack.

If you can get a hold of another MAF, try swapping it and see if that helps. It helped mine.

[MVOVER]

Eclipse's don't have a distributer, it has a coil pack.

Suppose that shows what I know about Asian cars:tongue:

Anyway, after reading about the BISS screw, this seems like a huge pain in the ass (just for idle adjustment). How the hell did I get myself into this? Not really looking forward to it after a day at work. Oh well..

Thanks

[DSM Power]

Originally posted by MVOVER
When it's idling it can't seem to find where it wants to idle; it goes up down up down, not as bad as it used to be but sometimes it goes from ~800 to ~1200 but mostly it plays between high hundreds and a grand.

I'd say the ISC.

[Strugari]

I am working on a 1992 Talon with the same problem right now, Code showed MAF, and TPS. Replaced both, idle still goes between 800 and 1500. Replaced ECM, (tested bad, and had a burnt circuit), still runs the same. I have now ordered a ICS, and will see in the next few days. Will let you know what I find.

Gary

[BEE18C1]

I had the same problem in my integra, but it was caused by a broken thermostat. My engine temp was always low while driving, and when i stopped it revved up and down like crazy trying to warm up.
when i replaced the thermostat i noticed the old one was stuck open. Keep an eye on your temperature gauge because the ideas placed before mine were also given to me until i noticed that my temp guage was low as well.

[GT2NV]

vaccume lines, or maf, thats what fixed my car

[Strugari]

Hi again,
Installed the ISC motor, and problem solved. Thanks for the help, and I hope this helps others.

[EK 2.0]

Glad you solved your woes man...But on the DSM's there are so many factors that affect idle man...all the adivce given kinda has to be gone thru one by one until the issue is solved...