Hey guys just figured I’d try and rack your guys brains. Before engine build car made 748whp and no fuel issues on e85 blend. After build only fuel side things that were changed were the addition of the WX port injection. We cannot get steady fuel pressure and under load car dips down to 15psi on low side readings and can’t over 5k rpm on dyno without running out of fuel. tried adjusting fuel pressure regulator on kit and still won’t hold steady fuel. My only thoughts are that the lines and extra volume in the fuel kit that was installed or creating a pressure drop and unsteady readings. Either that or the intake pump is going bad however when unplugging the fuses for the fuel pump on the WEAPON x kit the car seems to steady out idling a bit healthier as opposed to when it’s plugged in it seems more sporadic. What are you guys thoughts on why this could be happening , my next option is to put a mechanical gauge on the rail And see if I can figure it out that way because when I unplug The fuel pump fuse for the 2ndary it also powers down the connections for the fuel pressure gauge in the dash. Really pulling my hair out on this one spoke to church from Church automotive while I was getting it tuned and he’s confident something in the low side fuel system as the high-pressure rail is still seeing the designated psi it needs, just not feeding it enough fuel to keep it steady Sorry for my rushed demeanor in the video below but hope it gives you guys and idea thanks!

I’m babying it currently and redline is limited to 5k rpm on tune. If I adjust fpr pressure rises but won’t stay steady under load, any suggestions?

is it possible I need to boost reference the FPR or possibly could a check valve be malfunctioning inline? Sorry if the questions seem dumb I’m just trying to eliminate possible causes

Jesus I just noticed in the most inconspicuous placement on the poor install instructions that were combined to be a secondary fuel system and a Whipple supercharger install it said to tap Whipple for map and fpr reference wow. I read that freaking thing 100 times and missed it. Let’s give it a shot results soon

So adjusted fpr and the only way to keep it from crazy fluctuations is to set base at around 40 psi but that seems low even then so on peak boost it’s around 55 58 then occasional dips to 38ish. I can’t evem get it to duplicate the 70psi readings at idle in my posted video anymore, possibly indicative of pump failure or clogged filter ? guess I’ll check filter first ...