jjgti 10 Posted March 27, 2013 hey guys ive just had some work done to my head (2.0 16v 9a) new valves, skim and a general clean and de-coke and has had new valve seals etc put in. ive put it all back together and noticed it wasnt pulling as good as it used to so ive adjusted the dizzy and it has solved the problem (slow revs) but now it seems to idle at 1600rpm and is a pain when you come to a stop because it seems to want to "run away"..... i know there is a idle screw somewhere but not sure exactly where, and would rather ask some 1 who knows where it is or the best thing to do any help is greatly appreciated Quote Share this post Link to post Share on other sites
bmwcompact 10 Posted March 27, 2013 There isn't an idle screw on the 9a even though theres one on the KR. If you have put your belt on correctly (valve timing) and you've set your ignition timing correctly, it ought to be idling correctly. Assuming it was idling OK before you worked on the head why should it not do so now??? There is a mixture screw on the metering head, set at the factory and you should not adjust this. Owners play with this to try to sort out problems when its nothing to do with the mixture. Leave it alone as this wont be your problem!!! The first thing to check is that everything is back together correctly. Are all the hoses reconnected, including all those small vac hoses around the airbox and to the throttle body? Is the air filter fitted correctly/airbox lid fastened/all electrical connections in place? If there any air leaks on the inlet tract between meter head and manifold it screws up the system. Ordinarily idling problems are often caused by problems with the ISV (idle stabilisation valve). Its possible it could be sticking. Sometimes it can be successfully cleaned with brake cleaner. Its a bit of a coincidence if this is starting to play up now. Quote Share this post Link to post Share on other sites
jjgti 10 Posted March 27, 2013 yes i have made sure everything is back as it should be, and yeah i know of the fuel mix screw but i know the problem isnt there, its odd because it was ok before the head was off.... and it revs as it should now i have moved the dizzy slightly and the timing belt ect is all spot on. aaaaaaaaaaaaaaahhh ---------- Post added at 9:00 PM ---------- Previous post was at 8:56 PM ---------- it was ok on idle before i moved the dizzy but it was flat and had no power and the revs were slow, and now ive moved it a touch it idles high but revs as it should Quote Share this post Link to post Share on other sites
james153 0 Posted March 27, 2013 Sounds a little like the fast idle has only been caused by moving the dizzy. basically your problem should be traced to why the car was flat before, maybe camshaft timings? or a vacuum leak. just food for thought Quote Share this post Link to post Share on other sites
davidwort 0 Posted March 27, 2013 Yeah, unmetered air, i.e. leak in inlet after metering head somewhere, could cause high idle, or a faulty ISV, or over advanced base distributor timing. Quote Share this post Link to post Share on other sites
jjgti 10 Posted March 27, 2013 ok guys ill get on turning it back a little and will check the timing and vacuum lines again and will keep you posted on how it revs after Quote Share this post Link to post Share on other sites
jjgti 10 Posted March 28, 2013 Right ive turnd it back a touch and ive managed to get it to idle on around 1050 rpm and it feels fine to drive, ill keep it like this for a couple of days and see how it behaves Quote Share this post Link to post Share on other sites
