| I've been having a fuel pressure problem that was discovered during ZCon back in June. When I hit anywhere near full boost (> 16psi) the fuel pressure will drop off rapidly, about 7-10psi!). Diagnostics so far:
Replaced pump controller with known good one (no change)
Verified voltages on current controller under boost were good.
BRAND NEW fuel pump (no change)
Replaced regulator w/ aftermarket Aeromotive adjustable and removed stock regulator completely (no change)
Pulled fuel filter (K&N billet) and cleaned thoroughly (no change) This morning I decided to drive it and do some experimentation. To see if it might be a vacuum signal problem to the regulator I swapped some hoses around. I'm pulling vacuum from the driver's side of the plenum off the normal vacuum rail. However that hose is Teed into my SPI boost gauge. I first unplugged the T and ran straight from plenum rail to FPR. no change. Next, I switched the FPR to pulling signal from the hose that normally feeds the stock boost gauge (comes off the passenger side of the balance tube). No real change, although the drop doesn't seem as severe. I then played w/ boost levels. If I turn the AVC-R off so I'm running natural boost (which is around 10psi on my car) the pressure does not drop off nearly as radically and stays somewhat stable even at high rpms. As soon as I go up much higher than that the drop becomes quickly noticeable around 4000 rpm (which is actually BEFORE I hit full boost). It's a very strange problem and I'm not a fuel system expert so any suggestions would be very much appreciated!! In this condition the car runs dangerously lean so I have to drive it around like a grandma.
Meddle not in the affairs of dragons,
for you are crunchy, and good with mustard.
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