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

Throttle Problems

Discussion in 'A4/S4 forum(B5 Chassis)' started by diarmuid, Oct 5, 2007.

  1. diarmuid
    Offline

    diarmuid Member

    Joined:
    Sep 28, 2004
    Messages:
    81
    Likes Received:
    0
    [Oct 5, 2007]
    Hi All,

    I posted yesterday to say that I put my car into the garage as there was
    throttle problems with it as when the car was idling it would loose revs and sometimes cut out at traffic lights. I ended up changeing the belts, new water pump and other bits and pieces (they also diconnected the air con without telling me but thats a different story!). The throttle housing was also meant to have been cleaned out and the throttle settings reset.

    I though that all of this would have sorted my problems but it's still not quite right. It's no longer quite cutting out but it's still going down to about 500 revs from time to time and almost cutting out. The garage are 'meant' (this doesn't mean they did) to have cleaned the throttle housing so I'm not sure if that's the problem. It's definitely better than what it was but there's still something not quite right.

    I'd appreciate any comments on what it might be,

    Thanks
    #1
  2. Ads

    Ads

    [Sep 22, 2014]

  3. Jpc
    Offline

    Jpc Member

    Joined:
    Mar 30, 2007
    Messages:
    126
    Likes Received:
    0
    [Oct 5, 2007]
    Have you tried changing the MAF sensor?
    #2
  4. diarmuid
    Offline

    diarmuid Member

    Joined:
    Sep 28, 2004
    Messages:
    81
    Likes Received:
    0
    [Oct 5, 2007]
    Cheers for the response,

    Sorry for my ignorance but what's the MAF sensor? And is it a big job to change? They ran diagnostics and nothing showed up though

    Thanks,
    #3
  5. macattax
    Offline

    macattax Member

    Joined:
    Oct 4, 2006
    Messages:
    454
    Likes Received:
    0
    [Oct 6, 2007]
    I had a similar problem and it ended up being a a vacum valve which was torn.
    This is easy enough to diagnose by sticking your ear under the bonnet while the engine is running and just listen out for a pssssttt noise once you locate the general area use your finger to see if you can locate the offending valve (finger blocks hole noise stops proplem found).
    The leaking vacum pipe on mine was connected to the englne block.
    This might not be the problem for you but I had similar problems of the engine cutting out although not while stopped at lights mine only happened in third gear going up hill while turning into a sharp corner (very dangerous!) .
    #4
  6. johnyj
    Offline

    johnyj Member

    Joined:
    Jun 8, 2004
    Messages:
    264
    Likes Received:
    0
    [Oct 6, 2007]
    mine has still got a similar problem i have changed the maf and biometric sensor as vag-com suggested.
    but i still get the low revs hunting seems worse when engine is hot
    is yours the same worse when hot??
    #5
  7. diarmuid
    Offline

    diarmuid Member

    Joined:
    Sep 28, 2004
    Messages:
    81
    Likes Received:
    0
    [Oct 8, 2007]
    Yeah it does seem to be a bit worse when the car is warm. It's gone back into the garage anyway today. Hopefully when they run a diagnostic they will find the fault.
    I'll let you know how get on
    #6
  8. Jpc
    Offline

    Jpc Member

    Joined:
    Mar 30, 2007
    Messages:
    126
    Likes Received:
    0
    [Oct 8, 2007]
    sometimes the maf going bad does not throw any faults.
    #7
  9. stapo69
    Offline

    stapo69 All hail the mighty quattro!

    Joined:
    Mar 20, 2007
    Messages:
    969
    Likes Received:
    1
    [Oct 8, 2007]
    My S4 was idling real bad not long ago, turned out to be a boost leak, split hose onto one of the intercoolers, may be worth getting a pressure test done to see if there are any air leaks in the system anywhere, check the throttle body boot which joins to the throttle body and the f-pipe just under it see if there are any visible splits, common places these are, maybe knackered diverter valves too?
    #8
  10. diarmuid
    Offline

    diarmuid Member

    Joined:
    Sep 28, 2004
    Messages:
    81
    Likes Received:
    0
    [Oct 10, 2007]
    got the car back and they have reset the throttle settings and so far its running fine. It turns out that they didn't take the throttle body off to clean it (so not cleaned properly) so expecting some problems in the near future
    #9
  11. johnyj
    Offline

    johnyj Member

    Joined:
    Jun 8, 2004
    Messages:
    264
    Likes Received:
    0
    [Oct 11, 2007]
    nice one let me know if it stays ok ill get mine done
    #10
  12. diarmuid
    Offline

    diarmuid Member

    Joined:
    Sep 28, 2004
    Messages:
    81
    Likes Received:
    0
    [Oct 16, 2007]
    Car went a bit funny again the other day. So going to take the throttle body off and clean it myself. I've already got the gasket from Audi £2 so not bad. Hopefully that will sort it out.
    I'll let you know how i get on,
    Cheers
    #11
  13. johnyj
    Offline

    johnyj Member

    Joined:
    Jun 8, 2004
    Messages:
    264
    Likes Received:
    0
    [Oct 16, 2007]
    ive ordered the gasket aswell
    i have seen on hear not to open the butterfly flap
    let me know how it goes
    #12
  14. diarmuid
    Offline

    diarmuid Member

    Joined:
    Sep 28, 2004
    Messages:
    81
    Likes Received:
    0
    [Oct 22, 2007]
    I attemted to take of the throttle body but it was a bit more awkward than I imagined so I decided to take it back to the garage and get it done properly. Cost £79 (1.5 hours labour!) in the end. To be honest it hasn't really solved the problem.
    The car seems worse when its warmed up. I.m also getting hestiation when I'm driving around as well as the erratic idle cutting out at traffic lights etc.
    My only guess now is that it's the MAF. Has anyone any other ideas? I'm going to take the car back in again this week (4th time in 2 weeks!). I don't want to be going back every couple of days. I'm tempted to take the car to the main dealer to see what they say. Bit of a nightmare really
    #13
  15. diarmuid
    Offline

    diarmuid Member

    Joined:
    Sep 28, 2004
    Messages:
    81
    Likes Received:
    0
    [Oct 25, 2007]
    At last it looks as though it's sorted. It turns out I have dodgy air mas meter (or Naff MAF as someone referred to it on here once). It's a bit strange that it didn't show up the last 3 times they did a diagnostic on it.
    I have replaced the MAF and the car seems to be running perfectly again. Almost forgot what it was like to drive a car that wasn;t chasing revs and jerking every 5 minutes.

    When the put it through the diagnostic it showed up a failt with the altimeter (I didn't even know that cars had altimeters). However, this doesn't seem to be affecting the driving so its not too bad.

    I would recommend looking at the Maf before cleaning the throttle body (unless you're cleaning it yourself) as apparently you can test it by simply unplugging it to see if the problem persists.

    Thanks for all the suggestions opinions.
    #14
  16. johnyj
    Offline

    johnyj Member

    Joined:
    Jun 8, 2004
    Messages:
    264
    Likes Received:
    0
    [Oct 25, 2007]
    ive replaced the maff already with an audi one aftermarket ones dont match
    wish i could solve my hunting
    better get the twelve boar
    #15

Share This Page