Audi A4 1.9TDi 2004 B6 Fuel Cut-Out Problem

[lowtrawler]

I have a 2004 B6 1.9TDi Quattro Sport (130ps).

I’m having intermittent problems with the engine cutting out as if it is starved of fuel. Immediately following, I can use the key to turn the engine over for about 30 seconds to 60 seconds and it will come back to life and carry on as if nothing happened. This has been going on about twice a month for the past 6 months.

The problem only happens within a few hundred yards of starting the engine AND after stopping the car for a short period after a long journey. It never happens after I have travelled more than a few hundred yards and never after getting the engine going by turning over using the key. It has never happened when starting from cold. It seemed to improve following use of fuel additives and premium diesel but not necessarily so.
I have convinced myself that it is the fuel pump and so I should replace it. However, the fact that it happens after restarting following a long journey is putting a seed of doubt into my mind. Is there a thermostat that could be cutting the fuel as the engine cools down?

My problem is that it is such an occasional problem, I can’t recreate it in a controlled environment to listen for the fuel pump. I am convinced that the fuel is being cut-off and that it can’t be dirt in the fuel line or it would happen under other circumstances. Hence, it is either the fuel pump or some sort of thermostat that kicks in when the engine is cooling and which is sticking from time to time when I restart the engine. I am just unaware of any such thermostat. Does one exist? Where should I look?

I should add that I have previously raised the issue (Please Help Audi A4 Quattro Avant 1.9TDI Sport mystery engine cutout) and followed a few previous suggestions including:

• I have replaced fuel filter
• The garage have looked at the anti-shudder valve and confirmed that it is functioning properly
• There is no vacuum in the tank
• I have replaced Relay 109
• There are no faults when scanned

I need to get the problem fixed and the most likely candidate appears to be the fuel pump but that’s likely to cost me close to £500. I obviously don’t want to get the work done only to find it doesn’t fix the problem. Help!

[arman123]

what are you scanning it with? get it scanned with vcds when was the maf last changed on the car.

[nevo]

could be the lift pump in the tank,can get sediment in the bottom or look at the connector for crud,if you can get a vacuum oil extractor attach it at the filter and draw the fuel out see if it flows well,if its ok then suspect the tandem pump.

[pauldazzle]

As stated get it on VCDS/Vagcom before you start throwing money at it.
Coolant temp sensor & cam position sensor can often be the cause of temp related starting problems, & don't always throw a code so taking a look in VCDS engine measuring blocks is needed.

[SWARCUP]

was the fuel filter changed recently?

[lowtrawler]

was the fuel filter changed recently?

Yes, it was one of the first things I did.

As stated get it on VCDS/Vagcom before you start throwing money at it.
Coolant temp sensor & cam position sensor can often be the cause of temp related starting problems, & don't always throw a code so taking a look in VCDS engine measuring blocks is needed.

It is VCDS that was used to look for codes. Not sure what I would be looking for in measuring blocks, can you give me an idea?