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2.5TDI won't start

Les Woollam Jul 23, 2018

  1. Les Woollam

    Les Woollam New Member

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    Fuel filter full. No air visible in clear plastic hose from fuel filter to fuel pump. If I disconnect the steel fuel pipe from injector 1 and crank the engine, fuel spurts out. I can get the engine to (sort of) run on brake cleaner/holts easy start sprayed in the air intake, but the engine stops as soon as you stop spraying.
    Help!
     
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  3. S4_dan

    S4_dan Fire up the Quattro! VCDS Map User

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    Could be fuel pump. You may be getting fuel to the injector but the amount/pressure may not be sufficient. Try VCDS and see what it shows.
     
  4. Les Woollam

    Les Woollam New Member

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    Just checked with VCDS and got an inlet manifold flap motor fault. . . surely this wouldn't cause non-starting?
     
  5. S4_dan

    S4_dan Fire up the Quattro! VCDS Map User

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    Could do if it's blocking the air flow!
    Isn't that part of the anti-shudder valve when shutting the engine down?
    Try undoing it from inlet pipe and see it'll start.
     
  6. Les Woollam

    Les Woollam New Member

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    Ah, of course. . . the anti-shudder valve (inlet manifold flap) cuts the air supply to the manifold when the engine is turned-off helping prevent run-on. Therefore, if the valve doesn't open when the ignition is turned-on, the engine cannot start.
    The actual VCDS fault code says:
    19559/P3101/012545 - Motor for Intake Manifold Flap (V157): Open or Short to Ground
    Therefore, it would imply that the motor/solenoid cannot operate.
    Firstly, do you know which is the fuse to the Motor for the Intake Manifold Flap?
    Also, is there any way of manually opening the valve?

     
  7. Les Woollam

    Les Woollam New Member

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    The only valve I can see is the vacuum-operated EGR valve - I've taken this apart and it's fine with the flap fully open. The fault code would suggest that the inlet manifold flap (anti-shudder valve?) is operated by a motor (solenoid?), therefore must be located elsewhere. I've attached a pic of the EGR valve and also the complete engine bay if someone can point me in the right direction?
     

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  8. S4_dan

    S4_dan Fire up the Quattro! VCDS Map User

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    Looking at Ross-tech website, it would appear to be part of the egr valve?
    Can't remember what the egr looks like underneath on the 2.5 as I sold mine a few years back.
     
  9. S4_dan

    S4_dan Fire up the Quattro! VCDS Map User

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    Found this on a other forum:
    Re: v6 tdi intake manifold flap fault
    The intake manifold motor is on the intake pipe that connects to the inlet manifolds and the rubber boost hose fixes into it. It's on the right hand side as you look at the engine next to the power steering reservoir. It has a electrical connector and it about 300 od quid in dealer !
     
  10. Les Woollam

    Les Woollam New Member

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    I still can't locate the anti-shudder valve. However, I did as you suggested and separated the EGR valve from the inlet manifold thereby giving the manifold an uninterrupted supply of air. . . unfortunately it still shows no sign of firing.
     
  11. Les Woollam

    Les Woollam New Member

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    I'm suspecting that the fuel pump is delivering low pressure. Can I check this using VCDS just by cranking the engine?
     

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