shlude1

i have a brand new walbro 255...aem fuel rail...and rc650's stright from rc.

I was trying to tune yesterday and as soon as i hit boost my car would run really lean ...so i uped the fuel but then it would jump in and out of running like i tuned it and then really lean. I had an aem fpr on it but took it of but then it wouldn't jump back and forth, just run lean. I have a few ideas like not enough voltage to the fuel pump or maybe the fuel filter considering it the stock one but would like more imput.

so please enlighten me thanks.