1990 560SEC 334K miles as of 5/19, 1990 500SL (Euro Build) 67K miles as of 5/19
Hello all, I have a '90 560SEC, testing with a cold engine. New pumps. Rebuilt fuel distributor Pressure gauge in cold start port on FD and service port. jumped FPR to active pumps. I get 92psi/6.4 bar. Then it drops to 30psi pressure, but I can hear what i thought was fuel leaking, only to hear the sound is coming from the FPR. The "vacuum" line on the back side of the FPR doesn't leak fuel and I can feel a diaphram when I pull and puff on it. Are these signs of it being kaputt? Total failure? Next steps? Tests? Otherwise it can't be revived to my knowledge.....new or used? Does this part fail from gas being in contact with rubber for many years? Its got a spring mechansim in it, but the vacuum diaphram seemed intact unless there is anotrher main one. So buying a low mileage used one is not any better? So go new?