New Coyote crate motor intermittent lean and misfire

[bigjohnsonbikes]

Hi I just finished installing a brand new coyote crate motor in my 2015 mustang after I bent valves in the original one. brand new motor and I'm getting an intermittent lean condition and random misfires, usually mid throttle, cruising with the revs up aroung 2-3k. I upshift into overdrive and it clears itself up after maybe 10 seconds but it seems to keep coming back. This is a brand new motor complete with injectors, intake, throttle body, almost everything. I still have the factory fuel pump, o2 sensors and computer. I did upgrade to the BBK headers and no cats, and have the proper tune for those. Same difference on factory tune or new tune. Any of you guys have any ideas what could be doing this?

[1932]

Fuel psi?
Air leak?
Lose wire?

[edwardb]

Most of us here are running the Coyote crate motors with the Ford Performance control pack. Different PCM program, different fuel pump, none of the factory security. So our experience may not be helpful. Haven't had any issues like you're describing with the two I've done.

[bigjohnsonbikes]

Fuel psi?
Air leak?
Lose wire?

Thanks for the reply, my fuel pressure seems to be fine holding at 60 psi. haven't been able to find any air leak with starting fluid and I've gone over every wire I can see and I have touched but nothing still. It seems to be stuttering and surging just a little bit going down the road and the air fuel ratio is bouncing between 13.6 and 14.2 even when it's running better. I think I'm gonna just throw O2 sensors at it tomorow, that's about all I have left from the original system.

[wareaglescott]

Have you tried calling Ford performance tech support?
This guys are quite helpful