Dave's Evo X Build/The Life of Dave blog

[Murlo26]

Originally Posted by scheides

What other fuel system mods do you have? Do you have a fuel pressure gauge? If so what's it reading at idle? If not get one (I have a setup you could borrow/have but you'd need a gauge still). Maybe there's something going on with the blaq-ops kit where it is allowing fuel pressure from pump 1 to bleed off via the wye-that feeds from pump 2 when it is off.....this is one of the reasons I've been so adamant about sticking with a single pump.

Blaqops double pumper, 2nd pump turned on by progressive boost controller
DW1300s (normally, stock injectors temporarily).
MAP AFPR kit, with fuel gauge on the rail
stock fuel rail

At idle the fuel pressure is spot on, like 43ish psi. Shane has mentioned that about the wye fitting possibly bleeding fuel off the first pump. I assumed that is why I have always had issues with high rpm stomping on the car as the 2nd pump needed time to overcome fuel coming into it from the 1st pump. When I rolled into the throttle from a low rpm I never had an issue. Shane lowered my 2nd pump turn on boost level I believe last time on the dyno which seemed to almost get rid of all this.

The thing is even with that problem, I wouldn't think I would have an issue like this where the car is always adding fuel at cruise. It almost seems like there is a flow issue somewhere or maybe a bad o2 sensor?

I think I am going to open up the jegs fuel filter and clean it out. Then prolly pull my double pumper and see what everything looks like.

Originally Posted by simulatedwood

The way the fuel trims, and o2 readings are wandering, Id check the engine grounds to make sure they were installed according to the Factory Service Manual. This issues sound awfully familiar to the issues seen with bad grounds on other vehicles. I know it is a long shot, but it probable given the motor has been in and out of the car several times now.

Shawn

Its not wandering though, its only trying to add fuel and its a lot worse cruising vs. idle. Idle is 5% and cruise is maxed out at 12.5% and still not adding enough. So it gets worse as the car is cruising.