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faulty fuel pump symptoms

Discussion in 'A3/S3 Forum (8L Chassis)' started by nazS3, Oct 31, 2012.

  1. nazS3
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    nazS3 Member

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    Hi guys

    my s3 amk 2001 has problem starting from cold currently, turns over fine just wont fire
    i can hear the pump priming when ign is switched on

    got it started for few mins then it cut off again, & wont restart

    no fault codes at all, have fuel, have checked/replaced pump relay made no difference
    so could it actually be the pump in tank, as car has done 129k now
    thanks in advance
    #1
  2. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    Does it do this on a full tank? this normally happens when the tank is half way or less full... pressure drop occurs and takes a turn or two to get it back up enough to fire..

    Fuel pump can be tested with a fuel pressure gauge and a dyno... you can also log what fuelling is doing using VCDS to see if the pump is struggling under load/boost as the revs rise...

    <tuffty/>
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  3. karl210
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    karl210 Member

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    Ive got a feeling my fuel pump is running out of puff at high rpm, what blocks would need to be logged? thanks
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  4. nazS3
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    nazS3 Member

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    to be honest, car has approx tenners worth of fuel in it from empty tank
    & is parked on a slight incline driveway, car is currently off rd
    so cant fill up

    do you think low fuel is the cause, as i have no fault codes & can hear pump priming
    could the cts also be a posssibilty ? even though normally if the cts is faulty i would def get a code
    & only have problems starting from operating temp






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