stutter after fmic install

[92awddsm]

Finally got my front mount ic istalled today and now I have a really bad stutter/miss that begins between 6000-6500 rpm. Only getting about 4-5 counts knock during this time. The only change made other than the fmic install was I backed my mas calibration screw out flush and all new hard ic piping. Boost is set at 17 psi which is what it was at with the stock smic. Base fp is 40 psi with vac. disconnected. base timing is 5 deg. ngk bpr7es @ .028, eprom modded by Jeff O. for 550cc injectors, BOOST CUT ELIMINATED, 8250 rev limiter with no lift to shift and 4500 launch rpm, rest of mods in profile. I went from +4 high throttle to +15% with very little change. No boost leaks because I leak tested after install to 26 psi and only minor leak from throttle shaft and bov leak after 19 psi. I also had to tee my boost controller from bov line since I no longer have boost reference on j pipe. I didnt really get a chance to log any runs yet but will in the morning. Just wanted to see if anyone else has had this problem. I have also checked all vacuum lines and all wiring and nothing has gotten broken or disconnected. Sorry so long but I wanted to give everyone a basic rundown so noone will be telling me the obvious things that I already know to look for.

 

[Coldandafraid]

sounds like (besides a boost leak which you have ruled out) that the only change that could make a stutter is backing that screw out. Maybe try putting it back.

 

[92awddsm]

thats what I was thinking. I figured 11% richer on high throttle would take care of it but I need to start somewhere. I will log it tomorrow to see if there is anything strange.

 

[92awddsm]

Problem fixed. Swapped in a spare coil pack I had and now my fuel trims have gotten back to close to 100% Seems more airflow from the fmic was blowing the flame out at higher rpms. Guess it goes to show that problems already exist and we dont realize it. Who would have know a fmic would put more stress on the ignition system.