Hi All,

Getting a little frustrated at a problem i have been having for a while now which i cant get my head around, hoping someone here has gone through something similar or know about the issue.

The problem is apparent if i run anything higher than 19 psi the car will misfire or stutter. The only thing that has fixed this issue has been a test run that i made with minimum ignition retard limit set to 10 degrees, doing this allowed me to hit 24 psi with no stutter. Anything under 10 degrees has caused the issue to come back. AFR's are correct all through the rev range. MAP and MAF counts are very similar to each other. When the issue occurs the AFR's dont show any signs of lean or rich conditions and there is no nock in the logs.

the car is an evo 6 with a high compression setup using the standard ecu and ceddy's SD rom, car runs a pro12 CDI.

Things i have tried that have not fixed the issue.

Switching ROMS from SD to MAF etc
changing plugs
switching to oem coils
changing plug gaps

Thanks in Advance for the help.

 

Is it timed correctly?

 

Yep we timed according to GSC cam spec sheet.