bogey
10-28-2006, 01:12 PM
I have had the supercharger installed for a couple days now, and have been having knocking problems at 5K rpm and higher. After diagnosis, this is what I found.
I installed a fuel pressure gauge on the line going to the 5th injector. Using the diagnostic plug, I ran the fuel pump and was able to maintain 40psi. However, immediately after cutting the fuel pump, pressure dropped to zero.
I replaced the fuel pressure regulator with a used one borrowed from a friend. Now pressure will maintain 50psi+, and hold 40+ after 10 minutes.
The bad fuel pressure regulator actually allows air to blow through. Clearly a problem. (I suspected a FPR problem for a few years. The car has always taken a couple seconds of cranking to pressurize the system before starting.)
Now the car runs right up to redline without any problems.
I installed a fuel pressure gauge on the line going to the 5th injector. Using the diagnostic plug, I ran the fuel pump and was able to maintain 40psi. However, immediately after cutting the fuel pump, pressure dropped to zero.
I replaced the fuel pressure regulator with a used one borrowed from a friend. Now pressure will maintain 50psi+, and hold 40+ after 10 minutes.
The bad fuel pressure regulator actually allows air to blow through. Clearly a problem. (I suspected a FPR problem for a few years. The car has always taken a couple seconds of cranking to pressurize the system before starting.)
Now the car runs right up to redline without any problems.