Hi guys. I had this problem now for the past 3 weeks and so far 2 garages cant figure out what the problem is. On day after filing up with fuel, the car just cut out and wouldnt rev. AA came out and diagnostics showed it was cam shaft sensor. Went to specialist who said it was a fuel related problem (filter or pump), but after a flush of the fuel pipes the car was fine.....4 days later on a motorway it started backfiring, and went to stall. After a 30 minute rest it was ok but the next day it again cut out and left me stranded. Off it went to a BMW expert who diagnosed cam shaft sensor fault. It got replaced and the car was fine for a few days until it cut out again. ! Back to the BMW garage it went and they found that the sensor suppied was faulty and a new one was installed. Fine for a few days, and just on my way home tonight it nearly cut again....
Has anyone got any idea what this could be?? Petrol 4.4, with 130k on the clock

This might be a bit late but where did you buy the petrol
I've had problems in the past with supermarket petrol 1994 softail full stars n stripes custom harley davidson

No its not the petrol as i have filled up several times by now from different places. I am guessing that it could be the fuel pump but dont know how to narrow it down

I take it they plugged it in? There is nothing that can't be fixed with a hammer😜😜
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The car has left the service garage 3 times now running fine - but after a few days the problem appears as if its something that just builds up with use.....but i cant figure out what

I think the AA man may have been right... It takes 75 miles for the engine to fully learn new adaptions and if the garage reset the adaptions then it would behave for a few days...

Change specialists?

The camshaft sensor has been replaced but the problem pessists.

If the fault persists then maybe a wiring issue up to the sensor.

There are two sensors though, one for each bank, have they replaced the correct one?

Should be easy enough to check, just swap the two sensors around and see if the fault moves bank. If the fault stays where it is with a known good sensor then it's probably a wiring problem or an issue elsewhere that side. If the fault moves then it's a dodgy sensor.

As Cam-tech says, if they can't work that one out it's time to change 'specialists'.

I would check instrument cluster, sounds daft but that was my issue, needed to be replaced and apparently only by a main dealer

Is it definetly not a fuel pump issue? Why does it run ok when the mechanics have had a fiddle with it and then start playing up a few days later?

Hi ALEX1,

Did you get to the bottom of what was wrong ?

Thx

My local garage could not diagnose it so ended up having to take it to the main dealer. It was the fuel injectors - 4 out of the 8 had to be replaced. Dealer quoted £2k for the job! Yikes!

Cam-Tech-Craig wrote:

I think the AA man may have been right... It takes 75 miles for the engine to fully learn new adaptions and if the garage reset the adaptions then it would behave for a few days...

Change specialists?

I find setting the cruise to approx 59mph has them reset in about 20 motorway minutes


45 minutes idling will clear any that don't reset after that .

Having injectors tested and ultrasonicLly cleaned has worked for me in the past as an alternative to replacement