Starting issues after fuel filter change

Discussion in 'TDi - SEAT Diesel specific topics' started by Greegiecee, Apr 7, 2017.

  1. Greegiecee

    Greegiecee Loving my SEATs

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    Hi everyone,
    I'm sure this has been covered before, but I can't find specific answers.

    I have done 2 things to my car this week (06 Altea 2.0 TDi BKD engine)

    1. Diesel Purge - couldn't get it to work like on my old Toledo. After running for about 60 seconds, car stalled and won't start. Pipe work is correct and connections are tight.
    2. At last fuel filter change, exact same thing.

    Can someone please tell me what I am doing so wrong. I've been changing fuel filters and doing diesel purges for years without any issues on previous cars. I do turn the ignition on to prime the pump a few times, but it doesn't make a difference. This car seems to freak out the moment it gets touched. Is there a specific method to avoid (what I am assuming is air getting in to the system) from happening.

    Any help is appreciated.
     
  2. Speed-FReek

    Speed-FReek Senior Member

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    Are you simply just using an "ignition on" method to purge the air? When you turn the ignition on, all that does is prime (run) the fuel pump for a few seconds which is certainly not enough time to purge the amount of air that may have got into the system during a filter change. Even if you do this a few times, that will still unlikely be enough time to get rid of all the trapped air.

    It is recommended that you run the pump continuously for at least 60 seconds and in some case it cases up to 3 minutes. This can only easily be done with diagnostic equipment / software (VCDS, OBDeleven, Charisma etc.) unless you want to start messing about with running some temporary wires from the battery to the fuel pump supply wiring connector.
     
  3. propane94

    propane94 Bearded Ginger

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    As above, the car will not start as it will see no fuel pressure and shut it off. You need VCDS to run it and prime the system first.
     
  4. Greegiecee

    Greegiecee Loving my SEATs

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    Yeah I was simply priming by turning the key a few times. I was under the impression that this was enough on the 2006 models. I heard it only needed VCDS on the 2007 model and newer. Thanks for the feedback.

    Sheesh! What a mission just to change a fuel filter! I got it running eventually and it has been fine generally. Although it struggle to start when left for a few hours, but I think that is glow plug related. Unless there is still air in the system somehow (after almost a month?).
     
  5. Speed-FReek

    Speed-FReek Senior Member

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    A faulty cam position sensor also causes the engine to need a prolonged period of cranking before it fires up, however if that was the cause I would expect it to happen every time and not just after having left the car parked up for a few hours.

    I very much doubt that it is air in the fuel line.

    You best bet is to get a diagnostics scan done on the car which will avoid any guessing games.
     

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