PDA

View Full Version : Fuel system issue


knosker
08-09-2011, 04:00 AM
When I try to start my car on a cold start, it has a little trouble. I need to press the gas pedal to have it fire up, but after it has been running it will start up no problem. I think there might be restriction in the fuel system which is causing this, but I haven't run a fuel pressure check yet. I did replace the fuel filter, same problem. I was wondering if it might be the fuel pump? Any suggestions? Its an 04 330ci zhp in case anyone wants to know.
danewilson77
08-09-2011, 04:10 AM
Could it be bad spark? May try to swap plugs if you haven't done in a while. NGK BKR6EQUP.
knosker
08-09-2011, 04:15 AM
replaced the spark plugs, replaced the battery, checked the coils. I don't think it is anything electrical :(

The worst part is my OBDII reader can't detect anything in the fuel system, or at least I can't figure out how to diagnose it
danewilson77
08-09-2011, 05:03 AM
I guess it could be fuel pump.....injectors.....?
telijah
08-09-2011, 09:09 AM
Are you throwing any codes? Without codes, you'll really need to check fuel pressure. Here are some numbers from AllData Pro

Did this selecting a 2003 since I can't read your mind, but should be the same all around for the M54.

Fuel Pressure M54 Engine

Fuel Delivery Pump
Operating Pressure
bar 3.5
Delivery rate >/= 2.25 L / min.
X5 SAV
Typical current consumption
A >7
Passenger Car
Typical current consumption
A <9
NOTES:
RPM Range 620 - 800
Engine at operating temperature.

See: Idle Speed

Injectors and Lines, Fuel Pressure Regulator
Test pressure / nominal value.
bar [ ±0.02 ] = 3.5
Injector Valves, Start Valves
Testing pressure.
bar [ ±0.06 ] = 3.5
Marcus-SanDiego
08-09-2011, 09:09 AM
Nice post ^^

:chuck
knosker
05-27-2012, 10:47 AM
After almost 1 long year of the car taking a few cranks to start... I FINALLY FOUND THE PROBLEM. It was the darn fuel injectors!!! >:( 2 out of the 6 were leaking. No fuel pressure, so the engine became flooded every time I tried to start it. Finally replaced the leaking injectors and, as they say, the rest is history! I should have taken your advice and checked the injectors a LONG time ago, hah sorry! You guys def. know what you are talking about.