16th Apr 2003, 18:55

I also have had problems with idle speed fluctuation. This causes problems at stoplights, the engine stalls. I cleaned the throttle body with carb cleaner to no avail. Any indications on weather or not to replace the ECU?

18th Jan 2004, 01:51

HI again,

I'm the same lady that owns the 1990 Geo Storm GSI we've noticed some comments on the idle of the their Geo. Where is these parts that you guys are referring to ECU and the IAC?

It runs high when you first start it and then after it runs for a bit after it gets hot it starts speeding up and slowing down, and repeats until you kill it. Then it might not start again right at first. After you let it set for a bit it will. Also having to hold down the gas pedal when you go to start it and it's supposed to be fuel injected. It seems to be running rich on the gas. Any suggestions or comments. Could use them all. campfarm@mbo.com Thanks again. Dawn Campbell.

30th May 2004, 21:24

I really don't know much about cars, so you will have to excuse me. But if I am understanding everyone correctly, you are having problems where the cars motor speeds up so the engine is very load and then it shuts down. If this is the problem, my 1990 geo storm did that years ago back around 1993-94. Here we found out that the gas pedal somehow got bent and caused the car to idle hi then shut down. hope this helps someone.

25th Nov 2014, 02:19

The problem with the idle is the IAC controller. It has a bad o-ring on it, or you have to replace the ring or replace the IAC controller. I have 93 and 91 Storm GSIs. It's happened to two of them. I replaced the IAC controllers and it fixed the problem. Try unplugging it; if idle drops to normal, there's your problem.