Under bonnet fuel pump upgrade diesel - Page 2

David Lawrence · 4th April 2015, 09:02

Quote:

Originally Posted by p11dge

Im yet to run it that low but i cant imagine it being a problem as it would still draw from the tank as if the in tank pump was working i dont live to close to fuel stations to try that one

I understood that the in tank pump sucks fuel between the two halves of the tank. If you have it disconnected then i would expect that it will run out of fuel once you get to 1/4. Might want to carry a couple of cans in the boot for your testing just in case.

Either way your new pump looks good, and maybe with an added T piece in the tank pipework might get around the problem.

T-Cut · 4th April 2015, 09:08

Quote:

Originally Posted by p11dge

I'm yet to run it that low, but I cant imagine it being a problem as it would still draw from the tank as if the in-tank pump was working - -

I fear you misunderstand how the ITP plumbing is arranged. If the tank pump stops working, the UBP will draw in air via the ITP's priming valve if the fuel level falls to the critical point. The power of the UBP doesn't influence the problem.

More details here: http://www.the75andztclub.co.uk/foru...d.php?t=108535

TC

p11dge · 4th April 2015, 09:13

If the in tank pump sits on the left side of the tank there must be some kind of hose already there for the right side if the tank (looking from front of the car) as this fuel pump is big enough to not need the in tank pump but it still uses all its pipework surely it will sucking from both sides?

p11dge · 4th April 2015, 09:24

Quote:

Originally Posted by T-Cut

I fear you misunderstand how the ITP plumbing is arranged. If the tank pump stops working, the UBP will draw in air via the ITP's priming valve if the fuel level falls to the critical point. The power of the UBP doesn't influence the problem.

More details here: http://www.the75andztclub.co.uk/foru...d.php?t=108535

TC

Is there any way of capping or removing this valve?

MSS · 4th April 2015, 10:21

Having previously studied T-Cut's excellent description of the working of the CDT fuel supply system, I believe that the mod proposed here would at best only overcome the premature failure of the UBP following ITP failure. It doesn't negate the need for an ITP.

I admire people who are willing to experiment and come up with innovative solutions to real problems. However describing the OEM pumps as rubbish is a bit presumptuous given that they last between 100k and 200k miles. The pump being proposed here is of higher capacity but there is no reason to believe that it is not of low quality. Capacity does not equate to quality or longevity. Given the price of this alternative pump, it would be unreasonable to expect the same level of quality as the pierburg UBP originally fitted to the 75/ZT.

Well done for the willingness to experiment.

DMGRS · 4th April 2015, 16:53

I echo mss' comment - the OEM pumps do seem to last very well. Mine was OEM until around 6 months ago, and it wasn't faulty - just getting a bit noisy.

I'm glad the issue of 1/4 tank and the fuel distribution has been mentioned before you found out the hard way, as it'd be a faff removing your rear bench at the road side!

What our cars need is enthusiasts who aren't afraid to step away from the 'original' parts though, and for this I commend you.

p11dge · 4th April 2015, 22:23

Thanks for the support guys appreciate it ill keep trying

myrover2013 · 5th April 2015, 07:41

Ill be buying this one, great find

Falcon Flyer · 5th April 2015, 11:09

IIRC the later cars only had one pump, and I think it was the UBP? If thats correct, how did MGR get around the saddle tank issue of the pipe only sucking from one side??

David Lawrence · 5th April 2015, 11:31

Quote:

Originally Posted by Falcon Flyer

IIRC the later cars only had one pump, and I think it was the UBP? If thats correct, how did MGR get around the saddle tank issue of the pipe only sucking from one side??

Later cars only have the in tank pump but an uprated one.

4th April 2015, 09:13	#13
p11dge Regular poster MG ZT CDTI+ X-power 135 Join Date: Nov 2014 Location: lincolnshire Posts: 49 Thanks: 0 Thanked 22 Times in 8 Posts	If the in tank pump sits on the left side of the tank there must be some kind of hose already there for the right side if the tank (looking from front of the car) as this fuel pump is big enough to not need the in tank pump but it still uses all its pipework surely it will sucking from both sides? __________________ Just when things are going well !! Mods so far : 160 map, decat, synergy 2, manual boost controller, silicone and aliminum boost hose, bigger underbonnet fuel pump, projector headlights, full sports eletric and heated leather seats, android tablet install and refurbished anthracite Grey grid spokes

4th April 2015, 10:21	#15
MSS This is my second home Rover 75CDT, Jaguar XF-S 3.0V6, V'xhall Omega V6 Estate, Twintop 1.8VVT, Astra Estate and Corsa 1.2 Join Date: Dec 2007 Location: Suffolk Posts: 7,085 Thanks: 283 Thanked 624 Times in 440 Posts	Having previously studied T-Cut's excellent description of the working of the CDT fuel supply system, I believe that the mod proposed here would at best only overcome the premature failure of the UBP following ITP failure. It doesn't negate the need for an ITP. I admire people who are willing to experiment and come up with innovative solutions to real problems. However describing the OEM pumps as rubbish is a bit presumptuous given that they last between 100k and 200k miles. The pump being proposed here is of higher capacity but there is no reason to believe that it is not of low quality. Capacity does not equate to quality or longevity. Given the price of this alternative pump, it would be unreasonable to expect the same level of quality as the pierburg UBP originally fitted to the 75/ZT. Well done for the willingness to experiment. Last edited by MSS; 5th April 2015 at 15:48..

4th April 2015, 16:53	#16
DMGRS Discount MG Rover Spares Rover 75 CDTi, 2x MG ZS180 Join Date: Jun 2011 Location: Hythe, Southampton Posts: 11,320 Thanks: 456 Thanked 3,377 Times in 2,027 Posts	I echo mss' comment - the OEM pumps do seem to last very well. Mine was OEM until around 6 months ago, and it wasn't faulty - just getting a bit noisy. I'm glad the issue of 1/4 tank and the fuel distribution has been mentioned before you found out the hard way, as it'd be a faff removing your rear bench at the road side! What our cars need is enthusiasts who aren't afraid to step away from the 'original' parts though, and for this I commend you. __________________ Your trusted MG Rover specialist! Tel: 02380 001133 / Email: [email protected] We now have a 'chat' function on our site for even quicker replies. Give it a try! Remember - discount code FORUM5 for 5% off

4th April 2015, 22:23	#17
p11dge Regular poster MG ZT CDTI+ X-power 135 Join Date: Nov 2014 Location: lincolnshire Posts: 49 Thanks: 0 Thanked 22 Times in 8 Posts	Thanks for the support guys appreciate it ill keep trying __________________ Just when things are going well !! Mods so far : 160 map, decat, synergy 2, manual boost controller, silicone and aliminum boost hose, bigger underbonnet fuel pump, projector headlights, full sports eletric and heated leather seats, android tablet install and refurbished anthracite Grey grid spokes

5th April 2015, 07:41	#18
myrover2013 Posted a thing or two ROVER 75 CONNOISSEUR SE in copper leaf red Join Date: Feb 2013 Location: NORWICH Posts: 1,527 Thanks: 510 Thanked 134 Times in 111 Posts	Ill be buying this one, great find __________________ http://i196.photobucket.com/albums/a...h.jpg~original

5th April 2015, 11:09	#19
Falcon Flyer Gets stuck in R75 CDTi Auto Conn SE Mk1 Saloon Join Date: Feb 2010 Location: Crowthorne, Berkshire Posts: 665 Thanks: 190 Thanked 64 Times in 54 Posts	IIRC the later cars only had one pump, and I think it was the UBP? If thats correct, how did MGR get around the saddle tank issue of the pipe only sucking from one side?? __________________ The only 75 with a non-factory fitted, factory fitted sunroof!!!!