dhamilto

Some of the expertise from the "CIS update" thread might be applied here.

My 83SC starts nice, runs great, and idles correctly from cold until FULL temperature. Then (at full temp) it smoothly revs up to about 1400rpm and back down to about 1000rpm every couple of seconds with amazingly constant frequency. I have cleaned up the throttle housing and cannot see any problem with the vacuum tubes (can anyone tell me what size and how much of each size I need to replace them all) or air box. Anyway, the constant frequency implies that its either some malfunctioning control box causing this (I don't think there is one on this car) or there is a small hole in the vacuum system somewhere that allows vacuum to build up and then collapse. What do people think? Can anyone provide any tips on how to fault find this problem.

Thanks, Dean 83SC