New injectors (850x1300) against a previous PowerFC and the whole thing is running way too rich, especially at idle and low-rpm. This is despite my performing what I believe are the necessary adjustments to the injector settings in the PowerFC. The thing is running so badly I don't think I can nurse to my tuner's place (which is 25 miles away).

The detailed story....

The PowerFC had been running against stock injectors for a while and everything was fine (except for a boost problem). While tracking down a boost problem and replacing vac lines and solenoids (i.e. UIM and rats nest off) I decided to go ahead with my long term injector upgrade plan, specifically 850 primary and 1300 secondary. The 850's are brand new ND's and the 1300's are RC engineering bore outs of my old 850's (30K miles on them but certified as excellent).

After putting things back together I adjusted the PowerFC with the FC Commander to accomdate the new injectors. The new settings are:

Loc Pulse LagTime
Fr-Pr 64.5% +0.04ms
Fr-Sc +0.20ms
Rr-Pr 64.5% +0.04ms
Rf-Sc +0.20ms
Q-Pr 850cc
Q-Sc 1300cc

Idle and low-rpm primary are extrememly rich with burps of black smoke, almost to the point of not running. Mid-band and WOT is better but not perfect.

In troubleshooting I found the idle can be made 'normal but not until I adjust the pulse value down to the minimum of 25% on both front and rear...which of course makes anything other than idle not even run for being too lean. In any case, the problem appears to be symmetrical to both front and rear so I don't think it's a single faulty injector (unless both new primaries are faulty).

Bottom line, did I miss something? Should I have started out by resetting the PowerFC into learning mode? Something else?

Thanks in advance,
Jon

 

my bet is the 850's you put in the primaries are leaking causing your rich condition. You need to "tweak" those old secondary 850's to make them sit properly.

I recently said screw it with the makeshift fitment of trying to put secondary injectors into the primary fuel rail and just had a set of primary 550's bored to 850 to put in there...

K