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Quick lift pump query


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Defender 200tdi  -  Noticed diesel smell yesterday and had a look and the side of the engine and I've got diesel on the block and down on to the prop and chassis crossmember. Only small amounts - drips it seems and as far as I can see it's coming from the bottom of the lift pump where it's mated to the block. I've not run the engine and watched yet, but there doesn't appear to be any leaks higher up - the pipes are all intact and dry and the upper body of the pump is dry too. I've recently replaced the spill pipes on the injectors and they all seem ok and not the culprit.

So, if something fails inside the lift pump (is there a rubber membrane that creates a vacuum?) would this cause diesel to run into the rest of the lift pump and come out the bottom, maybe even through the lift pump casing?

Edited by Jocklandjohn
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Yep. I think the membrane just bounces up and down on the arm, pulls in, pushes out. It can leak and there's usually even a drain hole on the bottom of the pump so diesel will leak out as you describe. Time for a new lift pump. 

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57 minutes ago, reb78 said:

Yep. I think the membrane just bounces up and down on the arm, pulls in, pushes out. It can leak and there's usually even a drain hole on the bottom of the pump so diesel will leak out as you describe. Time for a new lift pump. 

 

Thanks Reb - I thought that might be the case. Now to see if anyone local can get a non-Bpart one for me by Tuesday!

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18 hours ago, western said:

Got a Delphi lift pump on my 200tdi, been on there fot a few years now, not given any problems.

I took your advice Ralph last time when the previous Brutepart one failed in a matter of weeks - and I bought a Delphi - this is it now 24 months down the road and appears to have failed! I'll see what the local motor factors have available as I need it in on Tuesday. I must say though when I fitted the Delphi, what a difference it made to the performance. 

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On 19 November 2016 at 9:09 PM, reb78 said:

Delphi seem ok. I got bored with mine going and fitted an electric pump!

Got an Allmakes one which looked infinitely superior to the Brutepart version so hopefully get it installed tomorrow - if I can get my hands to work at -2 or -3 or whatever it gets down to overnight!

Now then…this electric pump thing - how does that work? I understand the principle of the pump but its the electrical side I'm curious about - is it a constant fuel delivery or is there a 'pulse' delivery in time with the engine cam/crank rotation and demand? If the latter (like the lift pump) where is the signal generated?  (Alert - I am maybe talking utter rollicks - I have zero knowledge of these things so am guessing!)

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My install and discussion here

Mine is probably overkill. Boydie and TSD use smaller pumps than mine (akin to the type you'd see for an eberspacher heater I think) , but I didn't want to cut the fuel pipes and install in the wheel arch so I went for a pump that would lift rather than just push. 

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14 minutes ago, reb78 said:

My install and discussion here

Mine is probably overkill. Boydie and TSD use smaller pumps than mine (akin to the type you'd see for an eberspacher heater I think) , but I didn't want to cut the fuel pipes and install in the wheel arch so I went for a pump that would lift rather than just push. 

Thanks Reb - must a have a read at that.

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I had a Britpart and two Delphi lift pumps fail over a two year period.  I now have another mechanical pump fitted, but am unsure of the make, and I also have a permanently fitted, but not connected, electric pump.  I've fitted the suction and delivery hoses of the electric pump with the cut off connections from one of the failed mechanical pumps, so re-connection of the electric pump is relatively easy.  The power supply for the electric pump is taken from the power supply to the fuel cut-off solenoid.  I refitted a mechanical pump because the electric pump flow is far higher than the engine's fuel demand and I was concerned that it might overheat during hot weather due to insufficient flow through it.  I suppose that I should have connected the pump discharge to the spill back line as well as to the fuel filter.  That would have ensured adequate flow and I could have left it permanently in service.

Mike

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Lift pump diaphragm can split and you will then have a leak. You should also bear in mind that the fuel may well also be leaking into the sump. The lift pump is driven by the camshaft, so be careful of leaking diesel 'washing' oil off the cam lobe and causing lobe wear. Remove the oil filler cap and smell the 'oil'. If it smells of diesel, then don't start the engine.

 

 

Les.

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2 hours ago, Les Henson said:

Lift pump diaphragm can split and you will then have a leak. You should also bear in mind that the fuel may well also be leaking into the sump. The lift pump is driven by the camshaft, so be careful of leaking diesel 'washing' oil off the cam lobe and causing lobe wear. Remove the oil filler cap and smell the 'oil'. If it smells of diesel, then don't start the engine.

 

 

Les.

Thanks Les - I was aware of that. Oil seems ok but I'm changing it today or tomorrow just ion case.

 

Anyway I need help! 

I've just fitted the new lift pump (Allmakes) which is something I've done several times before. It went on ok, all the lines reconnected (and everything had been kept clean) and then swapped out the fuel filter too, and partly refilled the new one with diesel.  Engine on and bled the filter until all the bubbles are gone.

Engine running sweetly, took it down the road once it was warm and as soon as I came off the hill onto the flat and accelerated it choked and spluttered like it was starved of fuel. Limped home, stalling a few times as the accelerator pedal was pressed and nothing was happening, then the fuel seemed to flow again and it started running again. I could not get beyond second gear. 

It's been idling for 30 minutes running perfectly. I can rotate the crank until I get pressure on the lift pump lever and I can feel resistance but I can't get it to drive fuel up out of the filter bleed screw which I *think" I should be able to (I'm going to try this again just now). Also I've cracked all injector unions and all are pressured and firing out diesel when running.

So, it seems to be starved of fuel - any suggestions where to look next?  (It was running perfectly before I took off the old lift pump and FIP is recently overhauled and running perfectly).

Edited by Jocklandjohn
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I think it's been mentioned elsewhere.... Try releasing the fuel filler cap.

 

I was helping Mo with a similar challenge a while back ad the tank was under a vacuum.. Truck would tick over but not rev.

 

Run with cap off or lose and see if the problem goes away.

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Crisis averted! 

I ran the Eberspacher engine pre-heater to see what would happen (it's T'd off the fuel line going into the lift pump) and has a section of clear fuel feed hose. It was obvious there was air in the line, and the heater ran/cut out/ran/cut out indicating a fuelling issue.

I went back to the feed into the lift pump and despite having tightened the feed in fitting TIGHT it 'popped' when I put another turn on it, and then I got another two turns on it. Started, ran it and it started first time. Bled the fuel filter and it\s smooth and bubble free.

Out onto the main road (big hill) and it pulled up good style and then rattled along at 60mph on the flat at top. Just run the Eberspacher a few minutes ago and it spluttered and coughed a few times as it drew the line clear then fired up and is humming away nicely!

So, air in the lines was all it was. Oil changed too and new filter so thats me good to go I hope!

Thanks again for the assistance! 

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17 hours ago, Troll Hunter said:

I had a Britpart and two Delphi lift pumps fail over a two year period. 

Do you have a sedimenter?  What I found was that the non return valve would get stuck open from a small piece of dirt, causing the pumps to "fail" after I had removed the sedimenter.  Putting it back in the circuit stopped the failures.  This is on the 200TDI and earlier pumps.  The 300TDI pumps have an inlet screen, so probably do not suffer the same problem.

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Thanks for sharing your experience with sedimenters, Red90.  No, my vehicle does not have one, and never has, perhaps because it was originally a 3.5V8 and the 300Tdi is a later implant.  Perhaps I should get both a sedimenter and a water KO/drain pot and I've just been lucky until recently.  At least two of the failed pumps seemed to have ceased to do anything with the diaphragm, presumably because it had split, but opening the body is such a pfaff that I didn't investigate further.  If I've still got the old units I might have a go at opening one, and will post my findings.

Mike

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  • 9 months later...

Resurrecting this older thread.

Lift pump has failed AGAIN! This is the one I fitted November 2016 (see thread above), to replace the one I fitted 8 months earlier, which was a replacement for the one my local garage fitted a bout two months earlier which was duff, which they had fitted because the one I had on originally was knackered! (yes that's four lift pumps!). They variously - split, leaked and one had the inlet thread housing shear off (not overtightened either). 

Anyway - I broke down in Edinburgh a few days ago and had to get AA'd home. Suspected the lift pump had failed (and AA man agreed with me) but as it was Sunday I couldn't get a replacement. 

New pump bought and fitted yesterday and it started and ran fine. 

However, now I'm (apparently) overfuelling - EGT's are up by 100 C and turbo boost is coming in much earlier and harder and I smoke more in the lower rev range (off boost).

Are these pumps THAT variable or is it possible that I have finally got one thats working correctly and my (minor) fuel pump adjustments have tipped it into over-fuelling?

 

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Aye its got me flummoxed! 

Its increased  running temp across the range noticeably. Lift pump is one of Britparts finest so no idea who makes it, but I've also ordered a Delphi one  - the idea being to keep a working spare in the van just in case. I may swap for the Delphi one when it arrives and see what the difference is. 

Luckily it didn't break down the previous week as I was working miles up a hill track with a locked gate and a long walk to anywhere! Although the day before it broke down access to the wood I was working in was into a housing estate, drive over a kerb and down a pedestrian walkway, up a verge before an underpass and through some trees and long grass into the land that time forgot - the AA would never have found me!

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