Some more ideas - is the idle motor rusted/freezed in the open position ? Is the temperature-sensor ok ? if the resistance is too high or even open - then idle is set to a higher speed (simulates low temperature). Defect idle ECU ? Try another one. Is the idle motor humming/vibrating (100Hz) ? Elvis & 6548 Hello all. The idle speed on my D is too high ~1800 rpm warm. I've read the "Discussions on Idle Speed" and everything checks out. The throttle plates are correct, idle switch and ISC system work, no vacuum leaks, the brass screws in the throttle body are fully seated, all o rings, gaskets and seals in the plenum are new. I'm out of ideas for now and I'm hoping someone else can help. Could the backfire valves in the throttle plates be leaking? Matt Smith 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/