Check the resistance between pins 9 and 11 on the plug going to the idlespeed ecu. If it's open circuit, your idlespeed thermistor, or its wiring has failed. This is the most common cause of these symptoms. The second being the ECU itself. A vac leak wouldn't cause a high idle unless you fettled with the mixture at the same time, and it'd have to be a hell of a vac leak with a lot of fettling to get it as high as 3000. Martin Michael & Denise wrote: >Once again I must ask for the assistance of the experts on the DML as I can't seem to solve an idle problem I am having. Here's the background:I recently replaced the butterfly assembly in the air induction and everything seemed to go back together quite nicely. Upon starting the car I found that the idle had jumped up to 3000 RPM so I began to systematically check the usual suspects. All of the vacuum lines have been replaced and are connected, the brass screws on the assembly are tightened down, the throttle plates seem to be operating normally, the microswitch has been adjusted, and the O rings in the air horn have been replaced to make sure they are not faulty. Furthermore, the idle speed motor had previously been removed and tested by Dave Sontos when we were removing the air intake and was functioning properly. When Dave and I were looking at this problem last week he found that with the idle speed motor disconnected the idle dropped to 2000RPM whereas before all of this occurred my idle sat at app.850RPM. I'm certainly no expert on this matter but how could replacing the butterfly assembly cause this mess? It seems most likely to be a vacuum leak somewhere but I'll be darned if I can find the source of the trouble. Does anyone have some thoughts or ideas of what to try next? My neighbors are getting WAY too used to seeing me hunched over the engine compartment of my car! >Thanks, >Mike > To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/