535er 0 Report post Posted October 12, 2009 Ive got the M30 3.5 E34 5 series. Has been converted to manual but now i'm starting to have serious issues with the idle. When you go to take off and the revs drop, the engine tends to spike up to about 1500 - 1700 RPM then drops back to normal around 800. Also has recently started to hunt quite bad. Have been told could be AFM, oxygen sensors or electronic throttle but thought id go on here and get more opinions. Hope use can help!!! Quote Share this post Link to post Share on other sites
*Glenn* 854 Report post Posted October 13, 2009 It could be one of many problems. Seriously... get it scanned first. Check fault codes and live data. Then go checking many of the numerous problems it may have. It may just be something simple like a TPS switch or a minor air leak Quote Share this post Link to post Share on other sites
BM WORLD 1283 Report post Posted October 13, 2009 like glen said , get it checked, the idle control valves get sticky over time , so try cleaning it out etc . also double check for engine vaccuum leaks . check that the TPS switch is working and set correctly . Quote Share this post Link to post Share on other sites
kiwi535 538 Report post Posted October 13, 2009 i vote icv valve...the cylindrical device perpendicular to the hose near afm Quote Share this post Link to post Share on other sites
535er 0 Report post Posted October 13, 2009 It could be one of many problems. Seriously... get it scanned first. Check fault codes and live data. Then go checking many of the numerous problems it may have. It may just be something simple like a TPS switch or a minor air leak Have had it on diagnostics and nothing abnormal showed up so will start there cheers Quote Share this post Link to post Share on other sites
535er 0 Report post Posted October 13, 2009 i vote icv valve...the cylindrical device perpendicular to the hose near afm Have had it on diagnostics and nothing abnormal showed up so will start there cheers Quote Share this post Link to post Share on other sites
535er 0 Report post Posted October 13, 2009 like glen said , get it checked, the idle control valves get sticky over time , so try cleaning it out etc . also double check for engine vaccuum leaks . check that the TPS switch is working and set correctly . Have had it on diagnostics and nothing abnormal showed up so will start there cheers Quote Share this post Link to post Share on other sites
*Glenn* 854 Report post Posted October 13, 2009 Did they only check for fault codes ? or did the guy have a brain and check live data readings as well ?? Quote Share this post Link to post Share on other sites
Eagle 1662 Report post Posted October 13, 2009 You cleaned ICV? Quote Share this post Link to post Share on other sites