| I have noticed that my fuel pressure is dropping when the car is being driven around. I am assuming it is my fuel pump that is the problem but I hate to replace it without verifying it as the issue first. Of course it could also be the FPC but from what I understand when that goes the car usually just won't start. -Fuel pressure regulator and dampener have less than 3k miles, no fuel leaks through vacuum hoses. If I drive the car and give it gas a few times I notice that my a/f will start going a bit lean. When I stop and check the fuel pressure, idle is ~29 psi w/ vacuum. If all I do is drive it a short distance nice and easy the pressure will not drop and all is well including a/f (from a cold start). If I start the car from cold and let it idle up to operating temp the pressure will remain correct at ~36 psi with vacuum connected (~42 when disconnected). It idles like a champ. Also, in Nistune when I view the consult dashboard the fuel pump relay is highlighted in red, I swapped the relay but have not re-checked Nistune as it made no difference. I'm not sure what that signifies as the car starts and idles fine. I suspect the fuel pump because the system does not hold fuel pressure, it bleeds off over the course of an hour. I did change the 2" in tank fuel line that is known to cause a leak and that did nothing. Also the fuel injectors have been verified to not leak (many times!). Finally, these pressure readings have been verified with multiple gauges. Sorry for the long winded post, hopefully someone can point me in the right direction before I drop cash on the incorrect part.
'91 TT |
