Symptoms of Poor FPR

[Gdub]

Just curious what the symptoms of a poor FPR are?

[Kalevera]

Rough idle. Disconnect the vacuum hose and see the difference in how the car runs.


best, whit

[Gdub]

do u know if the FPR would cause complete power loss around 3 thousand RPM in every gear. Should u be able to hear the fuel pump standing next to your vehicle when the engine is idling? if so what kind of sound? My engine doesnt actually die or stall but in every gear around 3000 RPM it wont accelerate anymore and then a second or two later it will climb to 4000 rpm and do the same thing as it does a 3000rpm. This happens every time i accelerate. I now get about 11mpg City. I get a 1222 code, I have checked for vacuum leaks all over including the hose going from the intake manifold to the brake booster and yes there was a rubber plug, checked vac hose that goes from the Crankcase breather hose to the underside of the intake manifold, checked the hose that goes from the icv to the intake manifold, sprayed starter fluid all over, changed fuel filter(because it was overdue to be changed anyways), adjusted valves and new valve cover gasket( all to 0.012 cold), i use 92 octane gas, checked AFM and it opened smoothly. Pulled all my plugs out and checked the gap, they were all exact. They are bosch plugs with 30 K on them, new plug wires from Bavauto 5K ago (BMW). Help and advice wanted badly

[winfred]

fpr's die one of 3 ways, lock up and feed full pressure to the injectors, collapse and bypass most if not all pressure to the tank and rupture internally feeding fuel through the vacuum line. pressure should be between 40 and 50 psi depending on vacuum/no vacuum and gauge error, id clean the trace on the air flow meter with a nonresidual solvent, this may or may not fix the problem but it couldn't hurt, i've found free power by cleaning up a dirty one. another thing to look for is a shorting out wire from the ref mark sensor on the front of the motor, found a few rubbed through in the past that caused weird stuff when they grounded out on the motor

[Gdub]

Thank you winfred. I just went to the gas station and filled up(My tank was not empty it still had 5 gallons left). The problem seemed to have went away for the most part. I was actually getting 8-10 mpg city, and it now went up to 16-17 mpg city. I thought it could be condensation so i put a bottle of STP fuel treatment in. I drove around for a while and it hesitated during fast acceleration only a few times. I had a problem very similar to this on a road trip with my previous 87 325e because i was forced to fill up at a crappy gas station and i ended up getting fuel with water or junk in it. The car behaved in a very similar way to my current problem now. Has this happened to anyone? I will check what Winfred said and Post results.