tcbaurpower 5 Report post Posted February 18, 2013 Hi all, 1986 325i Ok so I am now unsure what to replace or how to diagnose the issue. When I start the car the idle will rise and fall for 30secs however will then idle normally. I have replaced the old hoses, intake boot etc. Replaced the intake and exhaust manifold gaskets, oil return o-rings. Any parts i could interchange to eliminate the culprit? I have 320i parts. Would a diagnostic check at BMW tell me anything? Quote Share this post Link to post Share on other sites
BM WORLD 1283 Report post Posted February 18, 2013 worn out air flow meter , sticky ICV , vac leak . fix these things and they will normally idle nicely Quote Share this post Link to post Share on other sites
_ethrty-Andy_ 2134 Report post Posted February 18, 2013 can just be adaptions in the ECU, its a free check. my 316i idled like you described, i had it plugged in to check something else and decided to erase adaptions while i was at it and i put it down to that fixing the issue. idled at 1100 initially then after a half day or so of driving, idle had dropped to bang on 700 and it still sits there now. (if you dont have a scanner thing aparently you can just unclip the ECU from its harness, leave it out for 10 minutes or so till it looses its memory then plug it back in, but i havent tried myself. someone thats done it can probably vouch) Quote Share this post Link to post Share on other sites
tcbaurpower 5 Report post Posted February 18, 2013 can just be adaptions in the ECU, its a free check. my 316i idled like you described, i had it plugged in to check something else and decided to erase adaptions while i was at it and i put it down to that fixing the issue. idled at 1100 initially then after a half day or so of driving, idle had dropped to bang on 700 and it still sits there now. (if you dont have a scanner thing aparently you can just unclip the ECU from its harness, leave it out for 10 minutes or so till it looses its memory then plug it back in, but i havent tried myself. someone thats done it can probably vouch) I will try that, thanks. I have read they may learn the information and apply that until new data comes through? Brent, I have eliminated all potential vacumm leak areas, every seal is new. How do you clean a sticky ICV? I will try replacing the air flow meter with the parts one, an 320i one wont be too different? Quote Share this post Link to post Share on other sites