Hello, just recently purchased a 2004 Audi A8. Check engine light comes on saying lean condition on bank 1 and 2. Fuel pressure gauge test readings are key on 49psi, starts fine and runs at 54psi, then about 30 seconds later fuel pressure drop to 29psi still idles and drives fine. Keep in mind, these have 2 fuel pumps, from my understanding, one comes on first to pressurize and start the car and has 54psi and runs for 30 secs, now I can pull the vacumn line off the FP Regulator and FP goes to around 60psi as it should. Then the other fuel pump kicks in fuel pressure drops to 29psi and upon pulling boff the FP Regulator hose, FP does not change, assuming not enough pressure for the FP regulator to regulate. Anyone had an issue like this, FP Regulator has to be good, maybe weak pump, but starts, idles and drives good. Maybe fuel injectors, has new fuel filter and new Mass Air flow.Any help would be appreciated.

Tags: Audi , Lean , Banks , 1 , and , 2