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A4 2.5tdi cold starting problem

Discussion in 'Diesel forum' started by Quattro john, Feb 13, 2008.

  1. Quattro john
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    Quattro john New Member

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    I have a 1999 A4 avant 2.5tdi v6 and have been having some problems in the recent cold spell with regards starting. The glow plug light comes on as normal,then goes out but it doesn't start for a few turns,as if the glow plugs are not working.On checking the plugs there were 4 not working so i replaced all 6.However its still the same.The local audi garage said after checking it out that it was the coolant temp sensor. So i got that and replaced it but still the same.I have checked the glow plugs again and there fine but there is no feed to the wiring for the glow plugs.So i wonder if anyone has had a similar problem or can tell me where the relay is,so i can check that.

    Many thanks John.
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  2. kite
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    kite Member

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    I think the relay is in the bulkhead area
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  3. Quattro john
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    Quattro john New Member

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    Found the relay ,its under the dash above the pedals. I have now replaced the relay and it is better but the next thing is to check the pump timing any ideas?
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  4. Quattro john
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    Quattro john New Member

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    The car has now been to the local dealer . When i spoke to them they recon'd the pump timing was miles out.It was adjusted and what a difference. The car starts great and the performance is nothing short of stunning. Its smooth and responsive, just what i would had expected from this car.Also the dealer was very resonable with the cost so thumbs up to the dealer. :arco:
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  5. jonplace
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    jonplace New Member

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    how much was it to get the pump timing checked / sorted ? and was it a main dealer ?
    my 03 V6 tdi seems a bit unsettled. A local indy said that it could be the fuel pump timing.
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  6. Gnasher
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    Gnasher Gansher

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    I have a similar problem, My A6 2.5tdi wont start, I think the timing for the fuel pump has slipped as it stopped wanting to start after the Power steering belt failed (replaced), could this have caused the timing on the pump to jump a notch? I have looked at all other possibilitys and have replaced fuel filter, fuel drip off lines. If it is the timing how can i check this is out?

    The car will bump start but seems to run a bit rich and once the engine is warm it will start after a struggle and then loads of white smoke out of exhaust
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  7. quattrojames
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    quattrojames Moderator Staff Member Moderator

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    A mechanic can set the fuel timing close enough, but to get it right it would need to go to a garage with Vag-com computer to do it.
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  8. Gnasher
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    Gnasher Gansher

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    I have Vag-com software and lead could i do it with this?
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  9. quattrojames
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    quattrojames Moderator Staff Member Moderator

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    Yes I guess so, I have no idea how though, sorry!
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  10. quattrojames
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    quattrojames Moderator Staff Member Moderator

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    Yes I guess so, I have no idea how though, sorry! It might be waorth a post in the Vag-com section as there will be more knowledge in there.
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  11. PW-Motorsport
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    PW-Motorsport Member

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    You can fine adjust the pump timing using vag com.
    With the engine running and warm, you need to go in to engine, basic settings, block 04. You will see a tdi graph box. Open this select the engine code and you should see an upper and lower scale, with a yellow line hopefully on the middle, if is not you will need to adjust the pump timing.
    Remove the r/h cam cover slacken of the three allen bolts, them move the pump pulley a small amount. Re-tighten the allen bolts and recheck the pump timing on vag com. repeat untill it is in the middle of the scale.
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  12. Gnasher
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    Gnasher Gansher

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    I have had a look at this and am not quite sure about this i did some screen grabs of the graph and am getting a green line at the top a blue line in the middle and a red line at the bottom this is on the tdi timing and i selected my vehicle type. there seems to be a yellow blip under the red line but it dosent seem to be forming a continious line across the screen.

    I also went into VC-scope and this is giving me 3 lines white at the top redline in the middle and a yellow line across the bottom under the redline.

    If you PM me i can send you the images if this will help have as not worked out how to get them on here easily.
    #12

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