Hello all, I'm working on a 94 Civic hatchback. I have a CEL on but no code, issue is intermittent and once it clears car runs good. If I check for code when light is off computer stats no issue. Once cel turns on runs terrible and very rough idle. If I jump service connector returns no code. Car is OBD1 running D16y8 tune up just done 3 months ago. I'm suspecting ICM is failing. ECU is chipped and if I create an CEL code would be given to me so I suspect ECU is running properly. Any help would be greatly appreciated, thanks.

 

BUMP

 

Replaced ICM and ignition coil and still same issue. Car has fluctuating idle and won't rev pass 4000 rpm on highway. If forced backfires. Any help?

 

Are you jumping the service connector and then turning key to ON?

 

Yes, I have checked the code and nothing given back.