Hello,

i recently did a rewire on my fuel pump (walbro 255) because i was noticing that my afrs were leaning out in the upper rpm range. I plan to get involved in autocross and more track events so i did it as a safety precaution to avoid catastrophic engine failure. What seems to be happening now, is my stock fpr is being overwhelmed by the now properly powered fuel pump. Im richer at least up to 4.5k rpms at which point my car is too rich to continue building power. I realize this can be fixed with an aftermarket fpr which i have had on order for a while now. What i am wondering is if i can, in theory, adjust my injector maps to run correctly in this situation as a temporary fix so i can run it at autocross this weekend, or would this overpressurization not be stable enough to build a map on (if that makes sense). I would obviously have to do some leaning out for this, but if i leaned it out to the apporopriate afr, would it always overwhelm the fpr the same amount and be a safe temporary solution, or could it sometimes decide it wants to regulate correctly and then supply less fuel pressure than needed and blow my engine?

i realize that the best safe option would be to skip autocross and wait for the fpr, but if somebody has a definite answer, ill roll with it.

-Carrington

s5. I have aftermarket fuel rails on the way as well.

Not that anyone should base their future endeavors off of this, but ive been working on a map between last night and this afternoon and its been responding predictably to changes. Thats not to say that it wont shoot me in the foot later, but ive been able to get it to the low 10s in full boost and its driving almost like normal. Probably better in some areas. Im gonna try to do a pretty safe tune with full boost being in the upper mid 10s, take a little fuel outta the transition area to try to decrease lag and then run it for the weekend unless someone who knows a little tells me otherwise.