2002 BMW 525i E39 won't start

Turbo6

New member
Having some trouble with an E39 BMW 525i. Been to 2 specialists so far, guys that know their stuff and there seems to be a bit of a gremlin in this car.

Car started surging as if running out of fuel then refused to start. No ECU errors so we replaced fuel pump and filter for good measure. Got a Bosch fuel pump from Diesel Electric and a GUD inline filter with the regulator from too.

Car still would not start and after swinging for a while it would suddenly take and then you need to feed in the accelerator to get it to idle. Once is idles on its own, it can be driven but if you floor it, it spits and misfires and if you on the open road then is a lack of power. After driving it for a while, switch off and it struggles to start again and feels like fuel pressure is low.

Even disconnected the airflow meter to check and changed ECU with a running car, no luck.

Question is then...which faults would the ECU miss, mostly mechanical right? So how do I diagnose this issue now. Like I said, car has been to 2 knowledgeable BMW makkies but both struggling to diagnose.
 

RAArmstrong

///Member
Gizmo knows these engines :thumbs:

Camshaft Position Sensor could cause hard starting but that would throw a code :dunno:
 

Turbo6

New member
RAArmstrong said:
Gizmo knows these engines :thumbs:

Camshaft Position Sensor could cause hard starting but that would throw a code :dunno:

I hear you bro but like my Z3 3.0 engine if disconnected the car would start then. My suspicion is the crank sensor itself. Anyone ever had one fail?
 

Mo63

///Member
Turbo6 said:
MO@CRAZYRIDEZ said:
would a faulty coil pack not give similar issues?

Could be bro but I'm sure would throw an error, swapping them out to be sure.

True my E46 did throw an error when the coils were shot.

Hope its not anything serious :nonono:
 

racing snake

New member
check the crank sensor wire hasnt rubbed through on one of the pulleys as that can also cause problems.

have you tried blowing compressed air through the fuel lines to make sure that there isnt perhaps some debris or dirt restricting the flow?

also check the fpr and fuel rail as the blockage could also be there

blocked injectors?

there are many many more things that could be the cause of the issues you are having but i just mentioned a few.

i hope you come right bro.:thumbs:
 

Turbo6

New member
racing snake said:
check the crank sensor wire hasnt rubbed through on one of the pulleys as that can also cause problems.

have you tried blowing compressed air through the fuel lines to make sure that there isnt perhaps some debris or dirt restricting the flow?

also check the fpr and fuel rail as the blockage could also be there

blocked injectors?

there are many many more things that could be the cause of the issues you are having but i just mentioned a few.

i hope you come right bro.:thumbs:

Maybe I should just listen to my inner voice and fit the x-pipe mod!:biglol:
 
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