Fuel pressure issue FIXED

2002 L322 TD6
Hi again all just a quick fuel pressure issue I am having.
Car runs fine (jinxed)
The other day decided to do a full service on her inc fuel filter, when I left my mates workshop it would not rev past 2,750 rpm and when I returned home I messaged Stustrong (who is a supeb fella and a god send) and he rang me back and we spent an hour in each others cars using INPA relaying info to each other on live data and due to the low pressure reading of 1,39 bar we both decided (he first I agreed as he is ver knowladgable) that it be the low pressure inline pump and so I ordered one and it came yesterday and fitted this morning, primed up (loads of fuel to filter no bubles in clear pipe to high pressure pump) started car and the same, reset codes and same comes back as before fitting it.

I have a mate owns his own specialist BMW workshop and he said on the X5 E53 its also common for the low pressure pump to go and they change the relay at the same time......are these the same ? I know the relay is in the boot but would the car even run if this were faulty ? its still running smooth and has same fault as before showing on codes.

Anyway Stustrong is sending me a FPS the one on top of the filter under the bonnet but has not arrived yet however as a test I disconnected the sensor on the car at the moment and (obviously fuel injection fault flashed up) it drove me home me driving harder than normal without fault and I know it will start up again now and do the same so would this indicate the FPS is faulty and giving a false reading causing the car to "think" it has a pre pump issue and going into limp ?
Also as the car is driving with it disconnected absolutly fine am I safe to drive it likr that ? ie no harm ?

Until this sensor arrives I know we will not know 100% if it is the FPS and until that time I will be worried in case its not but has anyone else had this problem or know of ?

As always huge thanks to all those that help.........humour welcome !

dazer200 said:

2002 L322 TD6
Hi again all just a quick fuel pressure issue I am having.
Car runs fine (jinxed)
The other day decided to do a full service on her inc fuel filter, when I left my mates workshop it would not rev past 2,750 rpm and when I returned home I messaged Stustrong (who is a supeb fella and a god send) and he rang me back and we spent an hour in each others cars using INPA relaying info to each other on live data and due to the low pressure reading of 1,39 bar we both decided (he first I agreed as he is ver knowladgable) that it be the low pressure inline pump and so I ordered one and it came yesterday and fitted this morning, primed up (loads of fuel to filter no bubles in clear pipe to high pressure pump) started car and the same, reset codes and same comes back as before fitting it.

I have a mate owns his own specialist BMW workshop and he said on the X5 E53 its also common for the low pressure pump to go and they change the relay at the same time......are these the same ? I know the relay is in the boot but would the car even run if this were faulty ? its still running smooth and has same fault as before showing on codes.

Anyway Stustrong is sending me a FPS the one on top of the filter under the bonnet but has not arrived yet however as a test I disconnected the sensor on the car at the moment and (obviously fuel injection fault flashed up) it drove me home me driving harder than normal without fault and I know it will start up again now and do the same so would this indicate the FPS is faulty and giving a false reading causing the car to "think" it has a pre pump issue and going into limp ?
Also as the car is driving with it disconnected absolutly fine am I safe to drive it likr that ? ie no harm ?

Until this sensor arrives I know we will not know 100% if it is the FPS and until that time I will be worried in case its not but has anyone else had this problem or know of ?

As always huge thanks to all those that help.........humour welcome !

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You NEED a sense of humour to own ANY Landy. An even BIGGER sense of humour to be an LZ-er... ¦~]

Jon Dor said:

You NEED a sense of humour to own ANY Landy. An even BIGGER sense of humour to be an LZ-er... ¦~]

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Ill join you on that mate, and to read my spelling as well lOl

dazer200 said:

Ill join you on that mate, and to read my spelling as well lOl

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Don't forget punctuation and grammar too!

Jon Dor said:

Don't forget spelling and grammar too!

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Like wot we duz.

tomcat59alan said:

Like wot we duz.

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aY lAdie

Inline filter in there? Might be thinking D3 just an idea.

Jon Dor said:

Don't forget punctuation and grammar too!

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Lol I did wonder when anyone would notice !
Story there, I left school young and all my life have tried so so hard to spell my words, 48 and I find out I am dyslexic ! at least i know now lol.
Just a shame I could not do a harry rednapp at Pomp lol

RangeRoller dt said:

Inline filter in there? Might be thinking D3 just an idea.

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Hi mate, the system is the same as on the E53, 1 pump in tank that pumps it over the top of the tank to another pump that pumps at 4 to 6 bar to the fuel filter that has a pressure sensor on top of this and senses the low pressure, from here it goes to the high pressure pump where there is a rail sensor that senses the high pressure.
I keep thinking over and over can only be the sensor and searched so many posts and when the low pressure pump gos they seem to fail to start.
Just wondered if someone on here had a sensor fail and do the same thing, I hate waiting for post !

Hi guys just to add to this thread and what the cause was in case it could help others in the future.

So as you will read above the fault occoured directly after I replaced the fuel filter where it lost all power and would only drive on 1/10th of power I would say.
All searching seemed to suggest that you change the secondry inline fuel pump at the same time as the fuel filter and many people saying htat their pump lasts 40k miles
Pump was replaced saturday (issue arose Wenesday) and still the persitant same problem.
Diognostics showed a low pressure reading of 1.39 bar and it only ranged down to 1.38 ( anything below 3.9 bar will show up as a low pressure fault and they like 4.1 to 6)
Stustrong had posted me a S/H FPS on Thursday morning but as of saturday it had not arrived so car was outside and I disconected the FPS from its connection on top of the filter and the engine had full power, I drove it 5 miles harder than normal no issues and checked for fuel bubbles (as if low pressure feeding the high pressure pump would be expected) but none, anyway I sat her up until the post came today and yay a FPS delivered thanks to Stustrong (top man)
Went out and fitted it and started up and hey presto what seemed to be full power !
I reset the error messages and took for a 20 miles drive perfect ! I even paid a visit to Silverlake had just had a e53 3.0D N57 come in and it had a FPS on it ! thats came home at a cost of £8 !
Only error coming up now is glow plug relay.

So as a rule i would say this.

Change the filter and pump at the same time, many places state between 10,000 to 25,000 miles I am going to go with 15,000 miles as this will be around about 18 months for me max so I will buy the kit on ebay around £45 and carry the old pump as a spare safe in the knowing I have a new pump and filter installed and a spare ! I use paranoia on service and repair as find this helps all brands.

If a problem develops I would suggest 1 of a possible 3 can from pump or FPR

1. No start up and a low pressurem error. Pump knackered replace it (with the spare !)

2. Engine starts and run's but low pressure error codes / sluggish. Check pressure reading if fluctuates with a maximum of 3.8 bar and rops down replace the pump.

3. Engine starts and runs but sluggish low pressure warning and readings are low and hardly fluctuate. FPS is knackered, Disconnect FPR and rev engine check for knocking sounds and air bubbles in clear pipe under bonnet, (if bubbles or knocking shut engine off)

Hope this post is of help to someone in the future.

I always end topics I post for this reason as I believe all posts should have a resolution even if we set fire to it before we find it !

A pump that only lasts 10K to 25K miles? That's crazy, more German engineering I suppose?

Datatek said:

A pump that only lasts 10K to 25K miles? That's crazy, more German engineering I suppose?

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Well I would agree with you on this mate that is mental, most are saying 40k but I am doing a filter change around hen so will just do both at the same time next time then I have a good spare