Both fuel pumps replaced on CDTi now wont start
 

Have replaced both pumps on my car now it refuses to start, removing the pipe after the under bonnet pump before the low pressure pump/filter shows its only pulling through a dribble of fuel similar to what could be sucked through a straw, I've tried to purge any air by running the ignition on 2 so the pump should expel any air but it's having none of it. I've done this 6 times now running it until the pump shuts off. What the hell is wrong!???

I had a similar problem, took me a week to find a tiny piece of plastic wrapping off a new piece of fuel pipe had jammed in pipe blocking it,,,,
if its not coming out at filter ,i disconnect other end of pipe and see what pressure there, and continue back from there,

Remove ubp and see what pressure is coming through from the tank?

As mentioned remove the UBP and check that there isn't the clear plastic protector for the inlet pipe stuck in the hose.

If not check that fuel is flowing through from the ITP - maybe the ITP pipework is letting in air?

Fuel is coming through but only a dribble... surely no fuel would come through if it was blocked by the protector?

Yes it can as the protector doesn't completely block the pipe.

Another check is to remove the outlet pipe from the tank - it is on the passenger side tank module, and see if you get the same flow rate from the inlet pipe to the UBP as you do from the tank outlet. If you don't there is a partial blockage somewhere in that line.

Thread moved to a more appropriate forum. Re-direct left in old. This may be the better forum as threads get ‘lost’ very quickly in the General Forum. ;)

I'm embarrassed to admit that the clear protector on the inlet was indeed stuck in the hose of the ubp! Removed and job done pump is now whisper quiet and car runs once again.

Look on the bright side - a quick and cheap fix. :D

Thanks for the update.

I'm also still embarrassed too buddy
I made the same mistake with mine a few years ago
And it was mike (noc) who found it (eternally grateful snivel,grovel etc etc
:bowdown:: )
Just shows what a great forum this is though eh gents :D
In my case the car had already been to a supposed BMW specialist who couldn't find the fault and was talking about pump seals etc etc :duh:
Same BMW man won't be seeing any more of my hard earned cash
Regards
Chris