Under bonnet pump

Kingfisher26 · 22nd February 2019, 15:31

Hi everyone, had a strange thing happen the other day so looking for advice now! Took my 03 CDT out, did about 10 miles and parked for about 5 minutes. Came back tried to start car and motor just turned over without firing, went to try again and realised I couldn't hear the UBP. So I popped the bonnet and just wiggled the pump which sprang into life. The car started straight away and I've since done more than 100 miles with no problems at all. The car has genuinely only done 47000, the cables and lines into the pump are all secure and there are no leaks.
My question is, should I be worried or put it down to an unexplained glitch?
As always any advice welcomed, many thanks Jim

markypicks · 22nd February 2019, 16:27

hi jim im pretty sure your car has 2 pumps one in tank and the other under the bonnet . when you turn the ignition on you should be able to hear both pumps. .. the under bonnet pump only runs for a bit to prime the engine . what happens is if the in tank pump fails the under bonnet pump will run .. when u put on your ignition put your ear to the drivers side rear seat and listen if u can hear the in tank pump running .. what happens is the in tank pump fails and the under bonnet pump will run but with only one ubp running it will cause strain on it because its working twice as hard . the itp transfers fuel to the ubp to take over hope it helps .. but it might just be a loose wire as you said rgds mark

Schotten · 22nd February 2019, 19:10

Same thing on my 03 too! Every now and then it happens, I was going just buy a spare as I reckoned it might end up just stopping one day and no matter how much “tapping” will revive it!

bl52krz · 22nd February 2019, 20:24

Take the electric plug off the top of the ubp and put some Vaseline onto The connectors in the top of the ubp. Then get the plug and push it on and off three /four times before you connect it back up. They get a white deposit on the pins and this causes the problem. Had the same problem with mine. My original ubp is still going at 103.000 miles. I have had a new one from Rimmers for the last eight/ nine years and hope I don’t have to use it.

Mike Noc · 23rd February 2019, 00:25

Quote:

Originally Posted by markypicks

.. what happens is the in tank pump fails and the under bonnet pump will run but with only one ubp running it will cause strain on it because its working twice as hard . the itp transfers fuel to the ubp to take over hope it helps .. but it might just be a loose wire as you said rgds mark

Not this old chestnut again.

An OEM UBP will run perfectly well on its own as long as you keep at least a quarter of a tank of fuel onboard.

Yes it has a little more work to do if the ITP fails, but I have run one for over 20k miles and it was still working fine when they were both replaced.

Arctic · 23rd February 2019, 09:05

Quote:

Originally Posted by Mike Noc

Not this old chestnut again.

Quote:

An OEM UBP will run perfectly well on its own as long as you keep at least a quarter of a tank of fuel onboard.

Yes it has a little more work to do if the ITP fails, but I have run one for over 20k miles and it was still working fine when they were both replaced.

HI Mike.
I agree and for that very reason I keep a least 3 tested pierburg UBP spare in the tools kit just in case anyone at the Nano meet as a a failure of both ITP & an waste of time after market UBP

22nd February 2019, 15:31	#1
Kingfisher26 Regular poster Rover 75 Classic SE CDT Join Date: Jul 2017 Location: Malvern Posts: 47 Thanks: 47 Thanked 22 Times in 7 Posts	Under bonnet pump Hi everyone, had a strange thing happen the other day so looking for advice now! Took my 03 CDT out, did about 10 miles and parked for about 5 minutes. Came back tried to start car and motor just turned over without firing, went to try again and realised I couldn't hear the UBP. So I popped the bonnet and just wiggled the pump which sprang into life. The car started straight away and I've since done more than 100 miles with no problems at all. The car has genuinely only done 47000, the cables and lines into the pump are all secure and there are no leaks. My question is, should I be worried or put it down to an unexplained glitch? As always any advice welcomed, many thanks Jim

22nd February 2019, 16:27	#2
markypicks Gets stuck in rover 75 saloon cdt club se re map 160 bhp Join Date: Dec 2018 Location: sheffield Posts: 558 Thanks: 227 Thanked 169 Times in 135 Posts	hi jim im pretty sure your car has 2 pumps one in tank and the other under the bonnet . when you turn the ignition on you should be able to hear both pumps. .. the under bonnet pump only runs for a bit to prime the engine . what happens is if the in tank pump fails the under bonnet pump will run .. when u put on your ignition put your ear to the drivers side rear seat and listen if u can hear the in tank pump running .. what happens is the in tank pump fails and the under bonnet pump will run but with only one ubp running it will cause strain on it because its working twice as hard . the itp transfers fuel to the ubp to take over hope it helps .. but it might just be a loose wire as you said rgds mark Last edited by markypicks; 22nd February 2019 at 16:48..

22nd February 2019, 20:24	#4
bl52krz This is my second home Rover 75 cdt club + Rover 2.5 KV6 Conni SE Join Date: May 2008 Location: Birmingham Posts: 11,387 Thanks: 6,587 Thanked 2,262 Times in 1,729 Posts	Take the electric plug off the top of the ubp and put some Vaseline onto The connectors in the top of the ubp. Then get the plug and push it on and off three /four times before you connect it back up. They get a white deposit on the pins and this causes the problem. Had the same problem with mine. My original ubp is still going at 103.000 miles. I have had a new one from Rimmers for the last eight/ nine years and hope I don’t have to use it. __________________ Great Barr, Birmingham.

22nd February 2019, 19:10	#3
Schotten Loves to post 75 Saloon Join Date: Feb 2007 Location: Glasgow Posts: 332 Thanks: 8 Thanked 10 Times in 10 Posts	Same thing on my 03 too! Every now and then it happens, I was going just buy a spare as I reckoned it might end up just stopping one day and no matter how much “tapping” will revive it!