5-Series (E12,E28, E34, E39, E60)Chat relating to the BMW 5-Series of all generations. Specific models include: BMW 518, BMW 520, BMW 520i, BMW 530i, BMW 528i, BMW 530i, BMW 518i, BMW 524d, BMW 525i, BMW 525e, BMW 528e, BMW 540i, BMW 535i, BMW 520d, BMW 525td, BMW 525d, BMW 530d, BMW 525i/xi, BMW 530i/xi. (BMW 5-Series Forum)
Help, anyone who has any ideas. My 525 is sitting in the driveway not starting. I recently resolved (so I thought) an overfueling problem which seems to have come back on me even worse than ever. The first time it seems my fuel pump was overpressurizing the fuel line which kept blowing out the diaphragm in the fuel pressure regulator. It seemed like the problem was returning slowly over the last couple of months, but now I can't even get it started. Last night it ran like only three of the cylinders were firing and I couldnt step on the gas without bogging it down or stalling. i barely made it home. This morning I got it running for a minute, that's it.
My question is, besides the plugs, plug wires, fuel pressure regulator, and fuel pump, might there be something I'm overlooking? My other question is, how many new menbers, like myself, join this forum as a result of BIMMERITIS (inflammation of a BMW)?
I look forward to all the well-thought out and lucid ideas any of you can offer. I am beginning to resent the car I once loved.
Bentley Manual says... "The fuel pump is capable of developing a higher pressure than that regulated by the pressure regulator. In the event the fuel pump check valve is faulty (stuck closed), make sure the fuel pressure does not rise above 6.0 bar (87psi). Damage to the fuel lines or fuel system components could result."
That being said... I would first get yourself a manual... Bentley is the best... and it has a complete 'how-to" on diagnosing the fuel system... from seeing how much pressure the pump puts out... to checking fuel check valves...
Has your car thrown any codes?... Is your CEL (check engine light) on? If so... get the code read.... by someone who can understand them and fully complete the diagnosis from the codes... not all codes will tell the exact problem... but 2 codes together might point to a good conclusion...
Get it looked at by someone that has the time and tools... fuel is rather hard to work with sometimes without the proper tools and area to work with...
The function of the pressure regulator is to relieve excess pressure as the fuel pump supplies far more fuel than the car needs. The only way you could overpressure the regulator is if the return line was plugged. Unlikely but possible..maybe crimped when lifting the car?
I have a 1995 525I that has fuel issues also. They initially replaced fuel
pump. I continued to have issues like you are having....not be able to start, if it
does start it kinda stumbles along until it just stalls sout again. The check engine light came on the last time. Took it back (towed it back) to mechanic and they proceeded to blow out the fuel line (had a blockage) and replaced
the air mass meter boot, breather valve, and the carbon canister....After
all of this it now seems to run better and so far (about a week) it is OK
Hope that helps!!!!
I suggest you check oxygen sensor. you car ir probably running rich air/fuel mixture, and I have the same problem with my 540..... turn ignition key on, stup on gas pedal 5 times and watch 'check engine" light blinking.... you should get the messaage,,,,
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