One thing for sure - under load, poor spark does yield the symptoms you describe. The light goes out because there is weak spark. The diagnosis probably rests in the effect the ECU is having on the coil. I haven't studied the relationships on the D but I do know that a match is essential. As an example, I recently opted to go with a Nology system because of the testing that was done by Nology. I noticed that a different coil is not a requirement (they provide an amplifier for the coil). I highly recommend the Nology by the way - A noticeable "kick" and significantly more power (keeps pulling) at the higher revs. Harold McElraft ? 3354 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/