I'm trying to solve an engine miss problem. 86 22re, doa 270, lc header, o/s valves. It misses above 2500 when sitting on the driveway, but doesn't miss under load. I did a search and someone one stated that the egr will cause it to miss when there is no load. Is this true?

i don't know about the load/unload part, but an improperley running egr can cause the motor to miss.

have you checked through all of the vacumn lines? also my chiltons manuel has a series of different ways to check the functions of the various vacumn operated parts. if you don't have a manuel i'd be glad to scan and e-mail them to you. but unfortunatley i won't be able to do it until next week.

the only other thing i can think of right now is the timing. if it is too advanced it will ping in the higher rpms when the mechanical advance advances. but under a load the vacumn advance retards the timing, i think, so that the motor won't ping. maybe it is set in a wierd spot where it would have that sort of behavior.

Check here:


NTSB (http://www.nhtsa.dot.gov/cars/problems/tsb/)

i would appreciate a copy of those scans when you get a chance as i am chasing ghosts in my 89 right now, thanks

2500 is about where EGR's come into play and start working (or not working). See if you cant drive it say in 3rd gear while keeping throttle steady between 2500-3000 rpm and see if you dont feel a hesitation. If so then EGR is suspect. Also you can disable it by plugging the vacuum line to the EGR and hesitation should go away.

2500 is about where EGR's come into play and start working (or not working). See if you can drive it say in 3rd gear while keeping throttle steady between 2500-3000 rpm and see if you feel a hesitation. If so then EGR is suspect. Also you can disable it by plugging the vacuum line to the EGR and hesitation should go away.