| Subject: | Low idle and stalling |
| Question: |
have a 1994 Mitsubishi Eclipse 1.8L manual transmission. I am having trouble with a low idle speed. When I am stopped and the A/C is on the idle is very erratic, it bounces from <400 rpm to >1500 rpm. It will very quickly stall if I don't give it some gas. It seems to work fine with the A/C off. The alternator is brand new and i still have this problem. I heard that there is a TSB on the Idle Air Control, is this my problem, or is something else wrong? Thanks |
| Answer: | Glenn, The most common cause for your problem is a malfunctioning Idle Air Control (IAC) motor. Your problem is commonly called "idle surge". When running the A/C, your engine will have an extra load on it. And with extra load, that will slow down your engine and the idle. Your IAC is responsible for raising your idle speed, and holding it constant regardless of the load applied to your engine. When you IAC is faulty, it will be unable to control the idle speed. Have your IAC checked and replaced if it's malfunctioning. Good luck! |