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How do i know if im in Limp Mode?

Nogwuy Jun 27, 2007

  1. Nogwuy

    Nogwuy Member

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    Hi, i fitted an N75 J valve and 710n DV befor fitting my boost gage. The gage only shows a peak of 0.3 bar, is this usual? Its an A4 1.8T quattro sport with no other mods (well a K&N panel filter). I have just recieved ny re-mapped ecu from chipped uk, and wanted to know if i should replace the N75 J with the original? what are the opther symptoms of limp mode, does it just reduce the boost, or does limit other things like revs and top speed e.t.c.? Thanks.
     
  2. AndyMac

    AndyMac Moderator Staff Member Moderator

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    You'll definately know if you've hit limp mode. Absolutely no boost and a top speed of about 60-70 if you're lucky.
     
  3. Nogwuy

    Nogwuy Member

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    Thanks for that. I've put my ecu back after the re-map and it seems much stronger woth more torque, but the boost peek is still the same at 0.3 bar? thought it might be due to the N75J so i replaced it with the original but no change? any ideas on if this is normal or do i have a problem? could i just have a duff boost gage? (it was a cheepo off ebay!)
     
  4. treblesykes

    treblesykes Member

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    try viagra
     
  5. PhilR

    PhilR One Ate Tea

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    Check your actuator, my car was producing very little boost and it turned out the wastegate actuator had totally failled allowing all the gases to escape down the exhaust rather than driving the turbo.

    When the engine is cold you can just say get your hand past the manifold and turbo to the actuator rod, see if you can move it back and forth, if you can its knackered.

    Failing that you need to look out for boost leeks as you should be seeing 1 Bar with a remap and a massive difference in acceleration and drivability.
     
  6. Nogwuy

    Nogwuy Member

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    Thanks for that phil, i will give that a try (although i dont actually know what or where the actuator is!). I had replaced the turbo induction hoses with silicone ones, so hopefully there are not any leaks there. I have also drilled the airbox as i had read that i would hear some 'wastsgate chatter' and get a slight blow off sound, but i cant hear anything! does this also indicate a problem? I got a mail from chipped uk, they said it could be the dv not holding boost, should i replace the 710n with the original (old) one to eliminate this? thanks guys.
     
  7. Nogwuy

    Nogwuy Member

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    Well i learned something new, and found the actuator! managed to get my hand (well finger tips) round the rod and it seems very solid as it didnt move in any direction. So hopefully i can rule this out as the cause of my low boost pressure? any other suggestions i can try?
     
  8. Beerzo

    Beerzo Masa'warty 3200... Talk To Me!

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    Double check all your new pipes that you put on to make sure they are all on correctly. As they have been moved touch could be them.

    How much did you drill you air box and with what size holes?
     
  9. Danielson

    Danielson Member

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    also worth checking is your throttle cable clip, on the inlet mani, have a friend apply full throttle ( with the engine off ) and check the throttle body is hitting the stop. i had the clip go awol and could only boost 5psi because of this! only 32p from the dealer. worth checking....
     
  10. Markey

    Markey Active Member

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    Have you cleared your fault codes after putting taking the N75J off?

    I had this prob with my old A4 would not go over 60-70mph ever after fitting one of these.
     
  11. Nogwuy

    Nogwuy Member

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    Thanks for all the tips, i checked the throttle cable clip, and its fine. I dont have access to vag com to clear any errors that there may be, so may have to take it to audi to have a diognosis done. I will try replacing the dv as it was a second hand 710n i put on, so i guess its worth checking before taking it to the stealership! i have probably drilled too many holes in the airbox (with hinesight) all 10mm on the underside, but was still reading the same boost pressure before and after, and i am going to get some tubing to feed in cold air from the lower bumper vent. can anyone with a 1.8tqs tell me what there boost readings are at some specific points please, i.e. tickover and various speeds/revs/gears so i can compair? do you think its worth getting a more pricy (accurate) boost gauge? Thanks alot guys.
     
  12. Markey

    Markey Active Member

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    Id see if you can get somone local with vag-com to help you out otherwise the stealers are going to drain your money, i have vag-com but not sure how far i love from Suffolk?

    I would put it all back to standard get the ecu diaged and any codes cleared then change the bits again one by one to see which if any are causeing the problems.
     
  13. Nogwuy

    Nogwuy Member

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    Thanks for the tip. Has anyone got access to vag com and would be willing to help me out! anywhere between Ipswich/Norwich? Thanks again to everyone who's posted.
     

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