2005 Golf 2.0 TDI 140 BKD Misfiring, cutting out, NO FAULT CODES

[volkswizard]

Hi,
Had a car recovered to me.
2005 Golf GT 2.0 TDI 140, BKD engine code, 78k miles, nice car.
Car would misfire underload, AA called, vehicle recovered to me.
Customer under impression from AA it was injector, not uncommon on 170 but 140? I guess anything can happen.
So scanned the car to work out which one, no fault codes stored.
Test drove it for 10 mins from stone cold, up to and beyond legal limit and not a splutter of any sort.
Called the owner and asked where he got AA diagnosis from, apparently AA man could hear the injector playing up - I'd forgotten my rule about recovery persons' diagnosis's - ignore 'em - if it wasn't for the sh1te Siemens Piezos, you wouldn't think injectors.

Swapped the fuel filter (which was pretty black) for a new one, fuel looked OK. Test drove it and now it was misfiring under load though idled OK. Clamped return pipe to artificially increase fuel pressure, no difference.
Unplugged MAF, no difference. Plugged it back in and now it would cut out at idle after around 30 secs, sometimes sooner.
MAF reading looked healthy.
Used VCDS basic settings test for EGR and this seemed to work OK.
Blanked off EGR pipe and no difference.
EGR specified and actual were quite a bit apart at idle but if I monitored this, nothing would change to make it cut out.
There is a MVB that monitors the injector fueling to maintain idle, number 2 was a postive figure, the others were slightly negative but all were in spec - nothing changes just before the car cuts out.

Replaced fuel pump for one from a 170 that was known good, no different.

Still no fault codes apart from an intermittent implausible signal from G40 cam position sensor but I think this is due to the cutting out leaving ECU live but engine stopped.

I am in the process of replacing the injector loom, am I pi55ing in the wind as no faults are stored?

Thanks
Andrew

[phil miller]

Had a skoda just like this in 3 weeks ago, it turned out to be water in the diesel, have you checked to see if the lift pump in the tank is working, it could be faulty and reducing fuel pressure to the filter (had a 140 passat do this)

Just a thought might be of help

[volkswizard]

I did wonder if it was fuel contamination, the reason I didn't investigate further was because owner had filled up from another station after the problem started to dilute any bad fuel he may have in the tank.
What may be a big clue is that the car drove OK on Monday after it had stood for 3 days.
If there was water it would be at the bottom of the tank where the pump scavenges from and it should have been worse UNLESS it was running off the swirl pot contents and the water had settled in the bottom of there but the fuel delivery was taken from the top of it?

Hmm..
Andrew
PS Yes I unplugged the original lift pump, no difference.
Fitted a known good one from a BMN 170 and it seemed a bit better but still missed when revved up. So I have ruled lift pump out.

[Peacey411]

Did anyone ever get to bottom of this, my bkd golf 140 has exact same symtoms!