306 erratic idle

rmgcook · Unread post by **rmgcook** » 21 Oct 2003, 18:05

97 306 XSI 16v. I have a problem which started a few days ago but it doesnt happen all the time. When I stop at lights etc, and dip the clutch, the revs drop to around 500, then back up/down etc. Sometimes the car stalls, other times it evens out at 750-800rpm. Other times it runs fine. I had a new catalytic convertor a few weeks back, but Im sure I had this problem once a while ago before I had the cat changed. A few people have suggested the stepper motor, which makes sense I guess. Are there any thoughts on this or anyone had the same problem? Anyway, I collect the stepper later today and i'll fit it tonight so fingers crossed it's that at fault! otherwise im stumped!

Paulmi16 · Unread post by **Paulmi16** » 22 Oct 2003, 01:30

We have a 98 XSI, and the idle can be erratic if the battery has been flat, or it has stood far a few days. It sorts itself out after a couple miles after the ecu does its 'learning process'.
The stepper motor can be cleaned as a temporary measure.
Paul.

rmgcook · Unread post by **rmgcook** » 22 Oct 2003, 14:14

I removed the original stepper motor and was about to fit the new one when I noticed it was half an inch shorter! so since I had the original one out already I gave it a clean up and its been running OK since.

wheeler · Unread post by **wheeler** » 23 Oct 2003, 03:27

do you mean the plunger on the original one was sticking out further ? if so then this part moves in & out when requested to by the ECU so may have appeared shorter.