Both fuel pumps replaced on CDTi now wont start

RJ303 · 9th March 2017, 10:26

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!???

vincentfishing · 9th March 2017, 11:01

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,

RJ303 · 9th March 2017, 11:04

Quote:

Originally Posted by vincentfishing

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?

Mike Noc · 9th March 2017, 15:28

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?

RJ303 · 9th March 2017, 18:10

Quote:

Originally Posted by Mike Noc

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?

Mike Noc · 9th March 2017, 21:32

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.

9th March 2017, 10:26	#1
RJ303 Loves to post MG ZT Join Date: Jun 2011 Location: Kingston Upon Hull Posts: 480 Thanks: 71 Thanked 25 Times in 24 Posts	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!??? __________________ MG ZT CDTi+ 160 remap/EGR bypass/Viton O-rings Last edited by RJ303; 9th March 2017 at 18:07..

9th March 2017, 11:01	#2
vincentfishing Loves to post rover 75cdt diesel saloon Join Date: Mar 2013 Location: Westgate on sea Posts: 441 Thanks: 21 Thanked 83 Times in 64 Posts	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,

9th March 2017, 15:28	#4
Mike Noc This is my second home Rover 75 CDT Manual Connoisseur SE, Rover 75 CDT Automatic Connoisseur SE & a Freelander Td4. Join Date: Jul 2009 Location: Hampshire Posts: 11,548 Thanks: 3,470 Thanked 3,119 Times in 2,247 Posts	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?

9th March 2017, 21:32	#6
Mike Noc This is my second home Rover 75 CDT Manual Connoisseur SE, Rover 75 CDT Automatic Connoisseur SE & a Freelander Td4. Join Date: Jul 2009 Location: Hampshire Posts: 11,548 Thanks: 3,470 Thanked 3,119 Times in 2,247 Posts	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.