Ok, so when i went for my tune, this is what evans said was the problem..

"Baseline on the car at 5 psi was 220 whp with the fuel pressure just dropping off like crazy. At 5 psi before changing the fuel pump, or rewiring the fuel pump through a relay from the battery the duty cycle was 70%. I had a huge amount of fuel thrown into the fuel map just to try to keep the a/f's in the 12's. The fuel map was completely unlinear, which is a clear indication that the fuel pressure was dropping.

The car had a stock fuel rail, so there is no where to hook up a fuel pressure gauge without drilling/tapping the fuel rail.

I vacuum/boost check the fuel pressure regulator up to 30 psi of boost and 30 in HG, both of which the regulator held steady and did not have any leaks from the diaphram. I had another stock fuel pressure regulator that I swapped on, and the identical results (a/f remained the same, and leaned out at the same spot).

I boost leaked checked the car before tuning, and it held 40 psi with no leaks.

The fuel pump was swapped with a brand new 255lph HP and filter kit, which helped initially. After a few pulls the pump sounded weird. I measured the voltage with the car running and it was between 9-10 volts. I make a jumper wire from the pump to the battery and the car held 13.5 volts and the pump sounded night and day better. Made a pull and the car just went 10:1 in the fuel map, and hit a wall were the fuel was jacked up to compensate for the dropping fuel pressure. Duty cycle dropped from 70% to 35% after making changes to the fuel map. I thought that fixed the issue.

Make some additional pulls with the car, and turned up the boost. The fuel map was linear up until around 12 psi, and at the top end of the pulls the a/f would go from a consistent 11.5 creeping to 12:1 range. I turned up the boost to 14 psi, and the fuel would go lean up top again. Duty cycle right now is at roughly 70% at 350 whp, which indicates fuel pressure is dropping again. I had to put the same wall of fuel at the upper rpm portion of the fuel map to compensate and get a flat a/f. The pump started to sound weird again."




Pretty sure i found the problem today, there are two crush washers i believe, one small, and one larger. The smaller one goes at bottom of the banjo bolt, the fuel line, then the bigger one on top, correct? I had the smaller one on top a believe thats why my fuel pressure was dropping severely because it wasn't letting fuel into the dampener, which then in turn lets it into the fuel rail. The washer was seriously so small, like hugging the banjo bolt that im surprised it let any fuel into the dampener. Fuel pump sounds much healthier now every time it primes now as well.

 

You guys know a lot more then me, a little confirmation would be nice from you guys, so i can atleast feel confident on my way for a re tune that i solved the fuel issue.

 

I would install a fuel pressure gauge to check the FP before wasting any more time making tuning appointments etc. A nice fuel pressure gauge is only a hundred bucks or so.

 

Not even 100 bucks, I bought a liquid filled guage for $35 shipped. Marshall I think.

 

But that's on the rail only. You can't see it while driving.
I don't even have a fuel pressure gauge. If I want to view fuel pressure I'll just purchase the aem sensor and wire it into the ems then view it through the serial gauge.

 

A fuel pulse dampener can also become faulty and cause fuel pressure problems.

Honestly, I would buy an IP fuel rail and a gauge for it. It will already have a port for a gauge so you wont need to tap it like you will with the stock fuel rail. It'll work with the stock fuel lines and look nice.

The reason why I say IP fuel rail is that the banjo bolt that comes with the IP fuel rail with let more fuel through a couple of holes as well as through the fuel pulse dampener. With the stock fuel rail, it'll just flow all through of your fuel through the fuel pulse dampener and the holes aren't too big in the fuel pulse dampener.

Just my 2 cents though and NOT necessary.

 

Thanks guys, I had the washer directly under the pulse dampener blocking every single hole from let letting it actually get into the top of the banjo bolt, so im 99% sure that was the problem.

 

Do a pull and see if the afrs go rich again. If they do then you know you improved your fuel pressure issue.

 

i would also add a bigger and new ground to fuel pump.

 

Hope that fix that issue so you can keep ur turbo kit.