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[GastronomicKleptomaniac]

Diesel 'bug' is only an issue if you leave the car stood for long periods of time with less than a brimmed tank, or repeatedly use dubious fuel

Possibility given that Jamester has just bought it, PO may have left it around a bit...

[JamesV6CDX]

Just for clarity... the day after I bought her.... full engine service, so Oil, all filters, etc.
When I changed the fuel filter, I filled the new filter up with the wynns diesel magic type stuff. It's also done 600 miles since on Shell V power diesel

[Broomies Mate]

Semi blocked Intercooler?

[JamesV6CDX]

Further to my previous posts on this, a bit of an update -

I have found out that, the only time it completely cuts out and give the "fuel injection system error" is when the tank is quite low, eg range reading around 60 miles. I popped 5 gallons in today, and, whereas before, I could replicate the fault code / shut down by driving at high revs - I now cannot.

However, even with a full tank, performance is still not right, and the car is intermittently holding right back, between 3 and 4,000 rpm. It has on a couple of occasions also failed to start first time, with the range on about 100/150 miles.

I looked at the pre-supply pressure on the live data, with a decent amount of fuel in the tank. This value is supposed to be 4 bar. Mine was 3.6 to 3.7 bar, so under, but not enormously - this dropped to about 3 to 3.1 bar when revving stationary - whereas it's never supposed to drop below 3.8 bar even when driving at full chat.

SO I concluded the pressure was lower than it should be. So, so many forum posts suggested the pre supply pump under the car is the common cause of this fault. So I went to the lovely Euro Parts. They only had a "HAAS" one on the shelf, for about £70 with a discount code, and I bought this. I got back and fitted it, and the noise it made was AWFUL! Also, the pre supply pressure, whereas on the old pump was 3.7 bar, with the new one, it was 3.4 bar, dropping to 2.5 bar when given some revs!

So to cut a long story the new pump went straight back, as it's absolutely rubbish, and can be heard over the diesel engine! I now have a genuine pump ready to fit, but I haven't got around to it yet.

I am thinking I may also just do the one in the tank as well, for the sake of futureproofing. Hopefully then my issues will also go away.

[Broomies Mate]

Best of luck with it James.  You certainly have the ability to get it right! 

[Sir Tigger KC]

You've got an air leak somewhere in your fuel system. 

[Kevin Wood]

There was also an overboost code in one of the logs you posted. That might explain why it suddenly goes flat when you really boot it. Maybe the wastegate / vane actuator is sticking?

[YZ250]

Just out of curiosity was the fuel filter a genuine part. The reason I ask is that my son had similar symptoms after he had just serviced his diesel a while back. A few miles after it had been serviced it would not rev in the higher band, would cut out just as he was pulling away from a junction and would need the codes clearing before it would re-start etc etc.
He tried swapping out the valve in the fuel pressure rail, Swapping pumps etc etc but with no change. After advice from a fellow owner he bought a genuine part fuel filter and it came back to life again. It's been fine since then. Not a bmw by the way.
Not saying it is that but thought it worth a mention. 

Did it go ok when you bought it or have you never booted it prior to this to find out?

[JamesV6CDX]

I fitted the genuine pump today before work.

Pre supply pressure exactly the same. 3.7 bar dropping to 3.1 when revved. No codes stored.

Test drive - 15 mile spanking, went well.

Then from nowhere lost all guts. Felt like a 1 litre. Struggling to pull at all. After ten mins back to normal

2 new codes

Pre supply pressure too low

Boost pressure too big

Arrrrrgh!!!!!!!!!

[05omegav6]

At least you now know why it was cheap

[Sir Tigger KC]

At least you now know why it was cheap

Oooo Bitch!     

[05omegav6]

At least you now know why it was cheap

Oooo Bitch!     

Not at all the pessimist in me always presumes there's a catch somewhere

[serek]

I fitted the genuine pump today before work.

Pre supply pressure exactly the same. 3.7 bar dropping to 3.1 when revved. No codes stored.

Test drive - 15 mile spanking, went well.

Then from nowhere lost all guts. Felt like a 1 litre. Struggling to pull at all. After ten mins back to normal

2 new codes

Pre supply pressure too low

Boost pressure too big

Arrrrrgh!!!!!!!!!

do you have number for those codes?

[JasonH]

The overboost error will cause "limp mode" until the ignition is turned off and on again. The car will feel horrifically underpowered when this happens.

This usually happens if the wastegate isn't opening quickly enough. It could be stiff or if vacuum operated you could have a vacuum leak or a faulty pressure converter. It could also be the adjustment of the wastegate (move the nuts on the threaded rod to ensure it's just closed when not being actuated).

I still suspect the fuel filter or a blockage in the fuel supply for the other issue.

[JamesV6CDX]

At least you now know why it was cheap

And on that note.... Why it was sold with a brimmed tank of diesel!!!

The car only properly misbehaves (and logs codes) with less than quarter of a tank..

I'm starting to suspect the in-tank lift pump. As opposed to the inline pump under the car?

I just can't see a physical turbo problem. If there was a turbo fault, why does it fly at half throttle, but is less rapid at WOT?

I still think this is a fuel issue, and the turbo code secondary? It only ever logs a turbo code, (boost too big) when there is the fuel code (supply pressure too low).

I've been over the system and found no leaks.

I can only think of the in tank pump. What else will make the pre supply pressure drop away under revs?

Thanks chaps