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Lift pump fault

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URL: http://www.brick-yard.co.uk/forum/forum_posts.asp?TID=94668
Printed Date: 18 Aug 22 at 14:54
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Topic: Lift pump fault
Posted By: PETE.T28
Subject: Lift pump fault
Date Posted: 22 Jun 21 at 22:05
Hi all 
Not been on here for a few years life been getting in the way. Have a  174 09 plate and have a question. Just changed the tandem pump as it appeared to be leaking and finding it hard to prime the fuel system. The filter is a 2 pipe so I disconnected the return pipe at the elbow fitting near the filter and put a container underneath, the idea was to prime the system using cycling the ignition on and off. After 10 or so goes I thought I would check the container see if any fuel was coming out of the elbo but found a pool of diesel under the van....this had been squirting out of the brown pipe that goes to the tank and should be the return. Am I missing the trick or has the lift pump failed as well. What's odd is disconnecting the black tube (flo) at the filter also gives a flow of fuel when priming weird eh!
Any thoughts anybody.

Pete



Replies:
Posted By: T5 TDI
Date Posted: 22 Jun 21 at 23:16
Hi Pete,  A two pipe fuel filter on a 174 is a new one on me. Confused  They probably changed things on the later vans.  If you can post some good pics here it might help.  I wasn't quite clear form your description but here's how it works on the old system if it is any help.  

The fuel from the low pressure pump in the tank comes up to the fuel filter, through the filter and then on to the tandem pump.  The pressure gets stepped up by the tandem pump then it arrives at the PD injectors and the real pressure increase happens as the camshaft squashes the injectors to inject the fuel as timed by the ECU.  The injection pressures are mind boggling!  The fuel is hot by now and goes back to the fuel filter (passing by a fuel temperature sensor) then through a fuel cooler radiator (easily visible under the floor) and then on back to tank.  

If you only have two pipes at the fuel filter neither of them can be a return.  Either you have no fuel cooler (which seems unlikely since the tank is plastic) or it must be plumbed in a different way on your later 174.  Perhaps they have decided the fuel doesn't need to go via the filter again on the way home.

If you disconnect the supply from the tank pump at the fuel filter inlet connection, you should get a short squirt of fuel for each cycle of the ignition.  If you don't get this I would say the tank pump is faulty or there is some restriction in the pipe.       


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2004 2.5 174


Posted By: PETE.T28
Date Posted: 23 Jun 21 at 06:41
Cheers mate. 
Yep it is different to older vans only two connections on the fuel filter.
 The return pipe is routed up near the filter then connected to the hard pipe 'brown' return line to cooler then tank. My understanding is the return goes into the lift pump lid and is  just a short pipe dropping fuel back in the tank. 
I just can't understand when priming it sends fuel up the flow and return when both pipes are disconnected in the engine bay....
Also there are less relays under the battery tray than my previous vans so obvious made a few changes here and there.


Posted By: T5 TDI
Date Posted: 23 Jun 21 at 09:33
What engine code is yours?  The online parts manual shows the 4 pipe filter for the 2009's with these engine codes.  Yours couldn't have been altered could it?    

Volkswagen Transporter 2009fuel line 1.9ltr. 2.5ltr. diesel eng.+ AXC,AXB,BRR, BRS AXD,AXE,BLJ, BPC,BNZ

http://www.oemepc.com/vw/part_single/catalog/vw/markt/RDW/modell/TR/year/2009/drive_standart/659/hg_ug/201/subcategory/201025/part_id/3686208/lang/e" rel="nofollow - http://www.oemepc.com/vw/part_single/catalog/vw/markt/RDW/modell/TR/year/2009/drive_standart/659/hg_ug/201/subcategory/201025/part_id/3686208/lang/e
   


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2004 2.5 174


Posted By: PETE.T28
Date Posted: 23 Jun 21 at 17:44
poss a bpc would have to check. It all looks factory. Tps supplied the filter off the reg so guess it's right..... Managed to get it primed and running by blocking off the return pipe to the tank and beading air from the elbow which is just after the temp sensor. Just kept priming with they key until I had a good flow of fuel. Connected her back up and she started on second turn. I think there is a problem with the lift pump but as it's not pumping whilst the engine is running it's not critical



Posted By: T5 TDI
Date Posted: 24 Jun 21 at 11:36
I have read of a couple of other cases where there was air between the tandem pump and the injectors.  That should just sort itself out but apparently that doesn't always work.  

It does sound like they have swapped the the route of the return flow pipe on late vans.  I can see the advantage of returning the hot fuel via the filter to keep it from waxing in very cold temps but perhaps it's not deemed necessary any more for some reason.  


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2004 2.5 174


Posted By: PETE.T28
Date Posted: 24 Jun 21 at 19:03
the previous owner had years of breakdowns and the garage could never fix it. I only know this as I bumped into a mate of his and he told me all about it. I guess that's why I bought it so cheap. 4k for a black combi sportline did seem a bit of a gift at the time....
Anyways I wonder if the garage replaced the fuel sender at some point and got the  flow and return mixed up and he's had problems ever since.


Posted By: T5 TDI
Date Posted: 24 Jun 21 at 21:37
You can see what the fuel temp sensor is recording live with VCDS so you can check if it is doing what it should.  I will post the the numbers here of the groups to look at when I get a chance.  Even if it doesn't mean that much to you it might help someone else in the future. :)   

I can't help much with the flow and return because I haven't seen the two-pipe version but I would find and check the flow from the pump and see what it does.  From your description it sounds like the tank pump is pumping fuel through both flow the and return pipes which must be wrong.

Edit- The data from the fuel temp senor is found in VCDS at group 007 in the first field.  It should be a  fairly close match to the coolant temp, intake air or ambient temp with a stone cold engine.  After that it should climb to a maximum of around 90 degrees C.  A poor fuel temp sensor can affect starting and running but a quick VCDS check live from cold could soon eliminate it as a culprit for any problems rather than just chucking in parts since it's not a very common fault.  


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2004 2.5 174


Posted By: PETE.T28
Date Posted: 28 Jun 21 at 17:45
I have vcds lite not sure if it will run that test. The result of fitting new tandem pump...no change van starts ok and runs fine until normal operation temp is reached then cuts out and is a pig to start again. . No DatC''s.   I have a spare used fuel temp sensor that I could swap out. After that I guess I should be looking at crankshaft or cam sensor or temp sensors.  


Posted By: PETE.T28
Date Posted: 28 Jun 21 at 18:05
Apears vcds lite will measure fuel temp can I check live with engine running?


Posted By: PETE.T28
Date Posted: 28 Jun 21 at 19:53
Okay Had her running from cold to just below operating temp on my drive with vcds running until she cut out....
Fuel temp rising slowly always about 10 degrees lower than coolant temp.
Lumpy running on tickover smoothed out with higher revs.
At tickover
Inj 1 -2.31
Inj 2 -0.75
Inj 3 -0.38
Inj 4 -1.29
Inj 5 +plus 2.99
Is it likely I need a new injector loom?
Still no fault codes.....


Posted By: T5 TDI
Date Posted: 28 Jun 21 at 19:57
Yes if VCDS lite lets you.  'Measuring Blocks' is the live data from the various sensors, you can't do any harm by scrolling around and having a look in measuring blocks but don't hit the 'switch to basic settings' button, stay with the live data.  

If you're sure that your fault is definitely temperature related I would investigate all temp groups from cold as the engine warms up.  If 062 is available, have a look there.  If it is, you could log the results from cold and see if anything unusual is happening when your fault occurs.  (VCDS lite might not offer this though).

062,0,Engine Cooling 
062,1,Coolant Temp. (G62),Engine Coolant
062,2,Coolant Temp. (G83),Radiator Outlet
062,3,Ambient,Temperature (G19)
062,4,Intake Air Temperature (G42)

Even if VDCS lite doesn't offer the logging option you can still just watch each sensor from cold and see if the numbers look consistent and sensible. 

 Edit- Crossed post..


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2004 2.5 174


Posted By: T5 TDI
Date Posted: 28 Jun 21 at 21:22
Originally posted by PETE.T28 PETE.T28 wrote:

Okay Had her running from cold to just below operating temp on my drive with vcds running until she cut out....
Fuel temp rising slowly always about 10 degrees lower than coolant temp.
Lumpy running on tickover smoothed out with higher revs.
At tickover
Inj 1 -2.31
Inj 2 -0.75
Inj 3 -0.38
Inj 4 -1.29
Inj 5 +plus 2.99
Is it likely I need a new injector loom?
Still no fault codes.....

Where are you seeing those figures?  Group 13/14 I presume?  If so, the figure for inj 5 does look a bit high.  There is nothing to worry about with a few small plus figures on the 2.5 's but a set of minus figures are more common for a healthy system at idle with no faults but I wouldn't replace anything (unless it's very cheap/easy) on that basis.  

If it helps, here are my my figures from group 13 (and 14 for cyl 5) from a while back (2.5 AXE ) at idle with a not quite fully warm engine.

Inj 1 -071
Inj 2 -054
Inj 3 -079
Inj 4 -009
inj 5 -016

I think I would start with a new fuel filter primed with neat injector cleaner if you haven't tried that already.  Otherwise maybe get injector 5 cleaned and tested by a diesel specialist.  I haven't personally seen the injector loom fault but most that I have heard about cause clear misfires.  Your call though! Tongue    




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2004 2.5 174


Posted By: PETE.T28
Date Posted: 28 Jun 21 at 21:41
Cheers for all the advice bud. I put a new filter in when I did the tandem pump and mixed s bit of injector with fuel in th filter the rest of the bottle went in the tank. This fault was random but now becoming frequent every time it's run infact. The van has 260k miles on her so  bit leggy.


Posted By: PETE.T28
Date Posted: 28 Jun 21 at 21:53
blocks 13 and 14 at 1500 revs
1  -0.71
2 +0.33
3 +0.42
4  -0.49
5 +0.42


Posted By: PETE.T28
Date Posted: 28 Jun 21 at 21:58
just an update when it cut out on the drive whilst getting the readings she was almost up to operating temp. Now she's stone cold and not starting, I'm sure if I keep cranking and give it some gas it will start eventually. But it does seem more like a fuel starvation problem. The lift pump in the fuel tank does..I'm assuming it only pumps when you first turn the key to start the van and not at any other time?


Posted By: T5 TDI
Date Posted: 29 Jun 21 at 08:56
I'm not sure about whether the pump should be running after priming.  The VW description on SSP 305 says 'The electrical fuel pump in the tank serves as a pre-supply pump, and pumps fuel to the fuel filter.' which is a bit of an ambiguous way to put it.  

I remember mine runs for a second or so and then switches off once primed.  It's possible that it restarts once the engine is going but I don't know for certain.  

I take it your fuel is a good normal clean colour and not grey by being contaminated with engine oil?  Also that the engine oil doesn't smell of diesel and is not high on the stick.


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2004 2.5 174


Posted By: PETE.T28
Date Posted: 29 Jun 21 at 09:51
It's a weird one when you search it on the Web most say the pump runs all the time the engine is running so maybe that's where the fault lies as it's doing strange things by pumping up flow and return.
I guess I'm just going to have to swap it out..





Posted By: T5 TDI
Date Posted: 29 Jun 21 at 10:09
Originally posted by PETE.T28 PETE.T28 wrote:

....as it's doing strange things by pumping up flow and return.




That part is very odd and is probably enough reason to take the pump out and test it at least.  It is a tank out job though.  


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2004 2.5 174


Posted By: PETE.T28
Date Posted: 29 Jun 21 at 15:51
yep is a pita but Ive dropped the tank on 3 T5's now so should be ok.


Posted By: PETE.T28
Date Posted: 01 Jul 21 at 18:47
New pump arriving tomorrow, just to be 100% sure I have pulled the flow  and  return at the engine bay and put a container under each, primed a four times and there's diesel in each cup. Interestingly there was about 50 mil in the return and 30 ml in the flow. I'm just going to go ahead and replace the lift pump. 
Will update with results.



Posted By: T5 TDI
Date Posted: 01 Jul 21 at 23:07
I don't know that two pipe set up but that test result can't possibly be right so I will look forward to seeing how you get on.  Poor lift pump performance does usually result in bad starting.  Good luck! :)

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2004 2.5 174


Posted By: PETE.T28
Date Posted: 02 Jul 21 at 21:13
Haven't got very far as new pump turned and was unbranded looks like a piece of junk supposed to be premium quality....that's GSF for you. Dropped tank old one out, looks tired and dIrty but ok.  Just to make sure I wasn't going mad I uncoupled the flow and return on the 05 camper filter and when primed fuel only comes out the flow....,
The 09 sportline doesn't appear to have a fuel cooler unless it's moved somewhere else it's def not in the usual place. So now have to source a decent lift pump as not fitting the GSF one it's going back,


Posted By: T5 TDI
Date Posted: 03 Jul 21 at 09:15
Looks like success to me. Smile  Another one to remember!

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2004 2.5 174


Posted By: PETE.T28
Date Posted: 08 Jul 21 at 07:38
Well got the new pump in before the footy last night and primed the system there is now a good flow of diesel from the flow pipe at the filter and minimal fuel from the return. The van fired up and seems to be smother, so test drive tonight to see if it's fixed....


Posted By: PETE.T28
Date Posted: 15 Jul 21 at 21:33
just thought I would give an update after changing the tandem pump, fuel filter, lift pump....diddly squat broke down again today so back to the drawing board...





Posted By: gregozedobe
Date Posted: 16 Jul 21 at 04:41
Bugger !   I hope you find the source of the problem soon.  If you can't it might be time to get a fresh set of eyes to see if they can find it.


Posted By: T5 TDI
Date Posted: 16 Jul 21 at 09:00
Oh no!  Is the fuel flow behaving itself this time though?  Or has it gone back to coming out of both the flow and the return like with the old pump?

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2004 2.5 174


Posted By: PETE.T28
Date Posted: 17 Jul 21 at 16:14
the fuel is only coming out of the flow now so that's all good. I replaced the starter and fuel pump relay no change. Next move is prob look at egr valve.


Posted By: T5 TDI
Date Posted: 17 Jul 21 at 21:50
When you say it 'broke down' what did it actually do?  Did it stop under load or refuse to start?  Are there any other odd symptoms like hissing when you take the fuel cap off?   

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2004 2.5 174


Posted By: PETE.T28
Date Posted: 18 Jul 21 at 09:21
just to add to the misery I'm now getting battery issues. It loses all its charge overnight, had it tested by motabitz and they rekon it's okay. Have pulled the fuse on the stereo equipment but it's not that. The alternator is pushing 14.6 volts. 


Posted By: PETE.T28
Date Posted: 18 Jul 21 at 11:12
Originally posted by T5 TDI T5 TDI wrote:

When you say it 'broke down' what did it actually do?  Did it stop under load or refuse to start?  Are there any other odd symptoms like hissing when you take the fuel cap off?   
slight hiss when fuel cap released so left it loose to see if it made a difference.
Same as before stuttering then cuts out and takes loads of cranking to start again. Always happens on a 4 ish mile plus journey when engine is up to normal operating temp.


Posted By: T5 TDI
Date Posted: 18 Jul 21 at 18:48
There is small chance that at your fairly big mileage the bad starting is caused by cracks in the head where the fuel gallery runs.  This would result in diesel getting into the oil (same as with leaking injector seals) so the oil level should rise and the oil might smell of diesel.  From the few cases I have heard about, the main complaint is long cranking to start since the cracks can introduce air.  I think you need some pretty specialist kit to pressure test the head for fuel gallery cracks.  

You could see if parking facing downhill improves the starting.  What this proves is that it is a fuel problem rather than an electrical problem.  Downhill parking can improve starting caused by a faulty lift pump for instance simply because it improves the fuel flow.     


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2004 2.5 174


Posted By: PETE.T28
Date Posted: 18 Jul 21 at 21:42
good call, I always thought that was on the older vans axd & axe. Oil level consistent just needs a top up every now and again. Never increases or smells of diesel when I change it. Charged battery but left off the vehicle tonight will check in the morning to see if it's gone flat on its own....


Posted By: PETE.T28
Date Posted: 22 Jul 21 at 18:21
well battery drain is intermittent, need to look more into that one. Think I have another problem developing... a few random pops from the top end so might be new cam time, maybe this is linked to the rough running!
Any recommendations in ferndown dorset area for capable mechanic....

Cheers


Posted By: PETE.T28
Date Posted: 29 Jul 21 at 20:57
Update ...
When I heard the popping noise from the top end I immediately thought camshaft but its a very irregular popping so I'm thinking injector  Had fault codes come up. Cyl 5 misfire, maf sensor, glow plug and some code uil. ..can't remember  now. Put a new maf in and all I get now is Cyl 5 misfire and that's after a 10 mile run and she starts to run a bit rough. Am I right in saying if it was an injector fault she would run rough from cold start and nothe when she gets hot?  Otherwise I'm thinking injector loom replacement...



Posted By: T5 TDI
Date Posted: 31 Jul 21 at 09:23
I think I would still check the cam first if it is popping at at all.  The popping can come and go hot or cold.  Usually they knock worse when cold and improve when warm but not always. 

Re the injector- I think it depends on what is wrong.  But the few I have seen misfire hot or cold.


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2004 2.5 174


Posted By: PETE.T28
Date Posted: 20 Sep 21 at 19:52
Bit slow fixing the van, have been using the Camper for work...
I took the van for mot and the mechanic there said it sounds like an injector chuffing. So could be the loom or injector on cyl 5.
I plan to strip the front end off next week and have a look. 


Posted By: PETE.T28
Date Posted: 22 Sep 21 at 18:26
I should prob start a new thread on injector looms but if anyone picks up this post Ive removed the rocker cover and the cam has a little bit of wear with a few lobes sharp on the edge s lost their chamfer is that bad? Can't really see the buckets...
I want to change the loom but I'm struggling to even disconnect the injectors. Can anyone just go through disconnecting the loom and how to Unplug and remove without taking the bearing cap off.

Thanks
Pete



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