Okay, I just reconnected my stock FPR, and I'm still getting fluctuations at partial 1/4-1/2 throttle!!!. The only thing I can think of is that maybe the length of the hose (I connected the stock FPR to the hose I had run to the AEM FPR) is flexing and causing the fluctuations. I'm pulling everything apart right now and checking it all again, and I'm going to put the FPR back in it's stock location and see if this makes any difference. If not, I really have no idea what to do next...

 

Are you using high pressure fuel injection rubber lines?

 

Yep, super expensive FI hose.

 

So, you are not running N20 anymore and you reconnect the stock FPR. Try zip tying all the lines at the connections. You probably have a vacuum leak under one of those.......

 

Ive vacuum tested my system, no leaks...

 

Dang, what about the fuel pump, what set-up do you have? Also, check your fuel filter as well.....

 

How is your stock fpr?

 

Walborro 255lph fuel pump, new fuel filter about 5k miles ago...

 

And this also may be an odd question, but are any of your lines pinched at all?.....

 

Nope, checked that as well...