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lean and dies when fast full throttle

Ford FE 390, Edlebrock RPM Performer intake, Stock reman vac-advance distributor with Pertronix ignitor 3 and flamethrower 3 coil.  "RV" cam, gets 15 at idle.  6 degrees initial advance.  spark plugs checked (look a little carbon fouled) and set to between .30 and .34. spark plug wires are new and properly routed into the management with the one pair crossed over as the factory service manual recommends.  Engine is new/rebuild with less than 500 miles.

Go-EFI Street 400 throttle body injection.

force fuel fuel pump.

It idles.  I've gone through and made sure the IAC is between 3-10.  It doesn't idle super-great, it feels like it's occasionally missing.  It revs up fine to 4000+ without issue, sounds good.  But if i fast open throttle the AFR goes 20+ lean and the RPMs drop.  If i keep it floored it will die, but if i let up it catches and returns to idle.

I'm hesitant to blame the spark plugs, but i'm concerned about that Pertronix igniter 3.  I have the never-used points that came with the distributor but i'm not quite sure how to set them for testing.  i also don't have a ballast at the moment.  Does my datalog show anything obvious?



1961 Lincoln Continental F.A.S.T. EFI 1969 Ford F250 390FE Go EFI 4 + Force Fuel

Definitely want to setup on Cam 1 for these specs.  This will richen the lower end of the rpm range.  Should help some.  Let it learn.  Needs time to adjust to the engine.

If lean spike continues adjust Accel and Fast Accel.  Increased values means increased fuel.  May also need to adjust the Accel decay and Fast Accel values higher in value.

I usually move in 10s and fine tune in 5s.

The ignitor 3 is not recommended to work with Fitech systems.  There has been electrical interference observed with this model.  Ignitor 1 and 2 work without issue.


Thanks.  Im running cam 1.


I’ve bumped the fast accel fuel to 40 to no effect.

im going to check with pertronix to see if there’s a better way to troubleshoot the igniter 3 other than replacing it.

1961 Lincoln Continental F.A.S.T. EFI 1969 Ford F250 390FE Go EFI 4 + Force Fuel

I recommend you move Accel, Accel decay, fast Accel and Fast Accel decay all up 20.  Just moving one will not make any difference.

Your ignitor 3 works fine.  Just doesn't play well with the Fitech.  Creates a tach signal issue.