1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

TQS judder/misfire

Discussion in 'A4/S4 forum(B5 Chassis)' started by griswold, Jun 30, 2012.

  1. griswold
    Offline

    griswold Member

    Joined:
    Jan 25, 2008
    Messages:
    341
    Likes Received:
    5
    Been having a a juddering for a second or two under heavy throttle, ease off and ok will judder with .5 bar but will go to 1 bar
    it happens at various speeds and revs.
    When its cold it dosn't happen straight away had full boost and no juddering and car went like a rocket
    after a couple of miles started to happen when warmed up.
    Waiting to get a pressure test for leaks, checked for visable and tightend hoses.
    Changed vac line, diverter valve, put new air mass sensor, coolant temp sender,fuel filter
    nothing when scanned.
    Think of getting a set of coils? ignition control module?
    car seems fine when cold? car 1.8 tqs remapped

    Ideas as to why fine cold ?
    thanks
    #1
  2. Bradderz_1988
    Offline

    Bradderz_1988 Dont replace it, Upgrade it !!

    Joined:
    Aug 19, 2010
    Messages:
    3,176
    Likes Received:
    101
    Check the Plugs they maybe arcing does it do it at idle at any point ???

    Had similar fault with mine was intermittant then after driving it a bit more it dropped a cylinder permanantly so disconnected the coils one by one and number two had dropped swapped the coil to a differant cylinder and it moved to that cylinder so swapped the coil for a good one and was fine after that.
    #2
  3. griswold
    Offline

    griswold Member

    Joined:
    Jan 25, 2008
    Messages:
    341
    Likes Received:
    5
    Changed the plugs forgot to put that in first post.
    Did that show up when scanning your dropped cylinder?
    #3
  4. Chriscooke
    Offline

    Chriscooke Clueless!

    Joined:
    Mar 2, 2012
    Messages:
    411
    Likes Received:
    18
    Did you change the plugs before or after the problem started? Could be a loose plug.
    #4
  5. aragorn
    Offline

    aragorn "Stick a V8 in it!" Staff Member Moderator

    Joined:
    Jan 30, 2008
    Messages:
    15,522
    Likes Received:
    300
    Airleak?

    Mums A4 was doing exactly this, and it was a split hose on the inlet manifold.
    #5
  6. griswold
    Offline

    griswold Member

    Joined:
    Jan 25, 2008
    Messages:
    341
    Likes Received:
    5
    Yes the problem started after plug change but thats when i noticed it.
    Probably a coincidence?
    Changed them for another set too.
    I'm thinking airleak but its fine when cold?
    #6
  7. aragorn
    Offline

    aragorn "Stick a V8 in it!" Staff Member Moderator

    Joined:
    Jan 30, 2008
    Messages:
    15,522
    Likes Received:
    300
    hers seemed better when cold too, got worse when it was hot.

    It was fairly random, mostly occurred at medium to large throttle openings between 2-3k or so. If you got it upto ~4k and gave it full throttle it would often take off at full boost with no trouble, which should have been the tell tale that it wasnt ignition related. I didnt find the airleak until after swapping everything ignition related, and the MAF though.

    Was one of the small bore hoses that goes to the tank vent valve or something, had split underneath and you couldnt really see it.
    #7
  8. griswold
    Offline

    griswold Member

    Joined:
    Jan 25, 2008
    Messages:
    341
    Likes Received:
    5
    Thanks, i was hoping the hot/cold running would help identify the problem.
    Maybe as the engine heats up the pipes warm up and the leak is worse.
    Would be great if it was just a leak and i could find it.
    Aragorn would be great if you could help identify the pipe or location where you had the split
    #8
  9. aragorn
    Offline

    aragorn "Stick a V8 in it!" Staff Member Moderator

    Joined:
    Jan 30, 2008
    Messages:
    15,522
    Likes Received:
    300
    to the right of the throttle body a hose comes off then turns 90degrees and snakes off to either the bulkhead or breather thing (cant mind which)

    It was that hose that was split.
    #9
  10. griswold
    Offline

    griswold Member

    Joined:
    Jan 25, 2008
    Messages:
    341
    Likes Received:
    5
    Just fitted new coils x4 problem gone:D
    #10

Share This Page