VW Passat 1.9 Tdi 2004 AVF engine - VW Passat will not start

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Wed 28 May 2014 11:51
VW Passat 1.9 Tdi 2004 AVF engine - VW Passat will not start - Athens1896
Hello

My car is a VW Passat 4motion 2004 with an AVF engine (3B6)

I recently changed the fuel filter on the vehicle but did not prime the fuel filter (believing that the pump will automatically fill the unit similar to petrol engine- learned my lesson.)

The car started and I drove it 30 meters down the road where the engine stopped presumably as the filter was empty.

I tried starting the engine a number of times but it would not start until eventually the battery went flat.

The battery was removed, recharged and re-installed in the car.

The fuel pump located in the tank does not work when turning the ignition key. The voltmeter at the pump connections shows 12V for a brief moment - not even a second.

The fuel pump located in the tank appears to work fine when connected to external power source. The hoses from the fuel filter engine intake was removed and bled from trapped air. The return line from the engine (i.e. the hose connecting back to the T was also removed and fluid very slowly came out.

Tried starting the engine with the external power source connected to the pump located in the tank but no luck.

The engine management light is also on.

Cleaned the EGR valve but that again did not make any improvements

Connected a WiFi ELM 327 unit to the OBD connector. There were no errors stored on the ECU. It did however mention DTI 1 misfire when i tried cranking the engine.

Is this still a fuel problem?
Is it worth removing the pump from the tank and cleaning the filter screen if it works?
How do tandem pumps fail?
Could this be a wiring issue to the injectors?
Preheaters do not appear to have voltage. Are they timed?

Does anybody have any ideas what maybe preventing the engine to start?
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Wed 28 May 2014 15:04
VW Passat 1.9 Tdi 2004 AVF engine - VW Passat will not start - craig-pd130

Have any fuses blown? I don't know if the lift pump in the tank has its own fuse ...

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Wed 28 May 2014 15:25
VW Passat 1.9 Tdi 2004 AVF engine - VW Passat will not start - elekie&a/c doctor
If it was running ok before the filter change,then it would tend to suggest you have a fuel supply problem.If you disconnect the output pipe at the filter then cycle the ignition on/off a few times,there should be a good flow of fuel to the tandem pump.perhaps The new filter is faulty/incorrect?is the o ring seal correctly positioned.
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Thu 29 May 2014 00:30
VW Passat 1.9 Tdi 2004 AVF engine - VW Passat will not start - Athens1896
If it was running ok before the filter change,then it would tend to suggest you have a fuel supply problem.If you disconnect the output pipe at the filter then cycle the ignition on/off a few times,there should be a good flow of fuel to the tandem pump.perhaps The new filter is faulty/incorrect? is the o ring seal correctly positioned.

This afternoon I diconnected the output pipe at the filter. The lift pump was running fine when the key was activated. It provided good flow.

I then removed the return lline from the engine to the T. This line also was left to bleed and fill a small bottle by running the pump on an external power source. A few air bubbles came up due to the disconnection of the filter output pipe. Cranked the engine and still did not start.

As mentioned in an earlier post the filter can't be connected incorrecly. The flexy hoses can't be crossed or placed back to front. There is no diesel leak from the T seals. What could be faulty with the filter?

Checked the ECU box fuse and relay 219. Everything looks fine fuse is intact and the relay operates as designed.

What else could it be?

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Thu 29 May 2014 00:11
VW Passat 1.9 Tdi 2004 AVF engine - VW Passat will not start - Athens1896

Have any fuses blown? I don't know if the lift pump in the tank has its own fuse ...

I can't find any fuses blown. The lift pump operates when the key is turned.

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Wed 28 May 2014 16:24
VW Passat 1.9 Tdi 2004 AVF engine - VW Passat will not start - A3 A4

Have you installed the filter the correct way around? If not discard get a new one, but fill with diesel first (prime).

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Thu 29 May 2014 00:14
VW Passat 1.9 Tdi 2004 AVF engine - VW Passat will not start - Athens1896

Have you installed the filter the correct way around? If not discard get a new one, but fill with diesel first (prime).

The filter can only be installed one way round - it is foolproof. The hose lengths and the t connector prevent it been installed incorrectly.

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