tcbaurpower 5 Report post Posted January 21, 2011 (edited) e30 325i 86 Hello. I have found that the butterfly valve gets a coating of oil which then will cause it to stick. The engine then has poor throttle response as the revs tend to drop when the valve hesitates to open and the idle hunts when cold. I know this is the cause because I just cleaned it again and the symptoms have again stopped. So... my Questions. Can anyone tell me what causes the build up of oil on the valve and is my periodic cleaning the only solution. My next step was to take off the throttle housing take it apart and do an even more extensive clean. I was also going to replace the hoses leading to it as they are most likely dirty as well. Click Me for Link Edited January 21, 2011 by tcbaurpower Quote Share this post Link to post Share on other sites
BM WORLD 1264 Report post Posted January 21, 2011 maybe your ICV idle control vlave is sticking (common problem) clean that out . check for vac leaks etc etc Quote Share this post Link to post Share on other sites
tcbaurpower 5 Report post Posted January 21, 2011 Yes the plan is to replace all the vac hoses, the valve and the rubber intake boot as part of this maintenance. Just so I am 100% the ICV idle control valve is item two as listed on the link I posted? Quote Share this post Link to post Share on other sites
tire 10 Report post Posted January 21, 2011 (edited) No, #2 is the TPS (throttle position sensor). Oil builds up through the intake on all the E30s I've owned, its natural. Comes from the breather hose from the rocker cover. Therefore I'd be suprised if this was the cause of your problems. I would clean the TPS, ICV, check for vacuum leaks, and possibly replace the intake manifold gaskets and injector O rings if you have time. The way the TPS mounts is adjustable. You want to have it so that it clicks with the throttle slightly open (1-2mm). Edit - The ICV is the tube thing off to the side of your rubber intake elbow. It should humm with the key turned 2 clicks. Edited January 21, 2011 by tastic Quote Share this post Link to post Share on other sites
tcbaurpower 5 Report post Posted January 21, 2011 Yes I have replaced and intend to replace alot of these 25 year old parts . On this engine I stripped it down and replaced a lot of seals, gaskets and I did do the o-rings etc. At the time I spent so many hours in the garage working on it I had had enough, put it back in the car and called it stage one complete. It looked good, and had no leaks however I have now decided to finish the job and make it perfect. It doesnt look good when you stall your car....and we all want reliable running cars at the end of the day. Cheers for clarifying the jargon. Quote Share this post Link to post Share on other sites
