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Hi all, new to the forums and have a question for you all (I tried searching but couldnt find anything similar :D )

Have a 1999 TT Roadster that has an annoying misfire that is intermittent. I am thinking that it is either faulty spark plug or faulty coil pack, I had a quick look but didnt have enough time to pull all the ignition crap out to get around to testing it!!! They could have made it a little bit more accessible :p any way my main question is someone told me that early model TT's had a problem with the coil packs is this true?? obviously I'll try some new spark plugs first as Im sure they'll be a hell of a lot cheaper than the coil pack.

Also one last question (all a bit new this Audi stuff :D) Every bit of information I've found in books and on the net say that the TT Quatro Roadster runs upto 1.9bar boost!! now I've been around turbo cars for a while now and I find it a bit hard to swallow that it produces this sort of boost, I mean nearly 30psi c'mon you'd need one big mother of a turbo to produce that sort of boost!!!, I've also got an RX7 turbo that runs 15psi and you can feel the difference so there is no way the TT runs twice the amount of boost as the RX7.

Sorry for such a long first post but I need some answers from fellow Audi lovers :D
 

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Originally posted by crazyboosta+Nov 30 2004, 05:09 PM--><div class='quotetop'>QUOTE(crazyboosta @ Nov 30 2004, 05:09 PM)</div><div class='quotemain'>has an annoying misfire that is intermittent
[/b]

You need to find a VAG-COM unit - it will tell you which cyls are misfiring - give you a place to start. Heres a previous post about what to look for when you have misfires.

<!--QuoteBegin-crazyboosta
@Nov 30 2004, 05:09 PM
the TT Quatro Roadster runs upto 1.9bar boost!![/quote]
Wrong... the 225HP TT has 1 bar (~14psi) and the 180HP TT has ~.8 bar (~11psi)

maybe you read that the engine can handle up to 1.9bar?
 

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Once you figure out which cylinder is misfiring then you could in theory switch the coil packs and or spark plugs after having checked to see that they are ok. A coilpack won't set you back too far. Could also be carbon deposits that might need removal.
 

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Discussion Starter #4
Ahhh thanxs bhb399mm yeah everybit of info said the waste gate opens at 1.9bar but figured it had to be wrong :D 14psi sounds and feels more correct. I will check that other post.

Originally posted by "getdamemo"
Once you figure out which cylinder is misfiring then you could in theory switch the coil packs and or spark plugs after having checked to see that they are ok
Yeah that was the plan untill I took the cover off and realised I had to pull a heap of igniton stuff off to get at them :p
 

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check the folowing:

coils
plugs
plug wires
check the ignition control module/ignition amblifier (aka power stage)
O2 sensor


to test if the coils are bad move the coil from a good cylinder to the misfiring one, and see if the problem moves to the new cylinder.

again, heres a good audi-forums.com thread about misfires
 

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Originally posted by crazyboosta@Nov 30 2004, 08:09 PM
Hi all, new to the forums and have a question for you all (I tried searching but couldnt find anything similar :D )

Have a 1999 TT Roadster that has an annoying misfire that is intermittent. I am thinking that it is either faulty spark plug or faulty coil pack, I had a quick look but didnt have enough time to pull all the ignition crap out to get around to testing it!!! They could have made it a little bit more accessible :p any way my main question is someone told me that early model TT's had a problem with the coil packs is this true?? obviously I'll try some new spark plugs first as Im sure they'll be a hell of a lot cheaper than the coil pack.

Also one last question (all a bit new this Audi stuff :D) Every bit of information I've found in books and on the net say that the TT Quatro Roadster runs upto 1.9bar boost!! now I've been around turbo cars for a while now and I find it a bit hard to swallow that it produces this sort of boost, I mean nearly 30psi c'mon you'd need one big mother of a turbo to produce that sort of boost!!!, I've also got an RX7 turbo that runs 15psi and you can feel the difference so there is no way the TT runs twice the amount of boost as the RX7.

Sorry for such a long first post but I need some answers from fellow Audi lovers :D
So have you gotten anywhere with the misfire? I have a 2000 TT that is doing the same thing.
 

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Hi there,

I have a 2003 1.8 TT and was having problems between 3rd and 4th gear only..intermittingly....it finally (after 7 months!!) turned out to be a fault in the hydraulics of the gear box.

They replaced them and its now good as new!

Cheers,

Edsters
 

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HI :)

THE DATA THAT YOU OBTAINE FROM THE BOOKS SAYS THAT THE BOST PRESSURE IS 1.9 BARS AND IS CORRECT. I'M TRY TO EXPLAIN YOU WHY.

AUDI TECHNICAL BOOKS SPECIFY THAT THE BOOST PRESSURE SHALL BE BETWEEN 1.7 TO 1.9 PSI ABSOLUTE PRESSURE. THE TRICK IS THE TERM ABSOLUTE PRESSURE. THE PRESSURE THAT WE READ IN A PRESSURE GAUGE IS KNOWN AS GAUGE PRESSURE. A THIRD PRESSURE TERM KNOWN AS ATMOSPHERIC PRESSURE MEANS THAT IS THE STANDART PRESSURE WHERE WE LIVE. NORMAL ATMOSPHERIC PRESSURE IS 14.7 PSI OR AT SEA LEVEL. REMEMBER THAT 14.7 PSI = 1 BAR.

WITH THE FOLLOWING ENGINEERING FORMULA WE CAN CONVERT ABSOLUTE PRESSURE TO GAUGE PRESSURE THAT IS THE ONE THAT WE NEED:

ABSOLUTE PRESSURE = ATMOSPHERIC PRESSURE + GAUGE PRESSURE

THEREFORE

GAUGE PRESSURE = ABSOLUTE PRESSURE - ATMOSPHERIC PRESSURE OR

GAUGE PRESSURE = 1.9 BARS - 1 BARS

GAUGE PRESSURE = 0.9 BARS IF WE CONVERT BARS TO PSI USING THIS EQUIVALENCE 14.7 PSI = 1 BAR

THE RESULT IS:

0.9 * 14.7 = 13.23 PSI.

FINALLY WE OBTAIN THAT THE MAXIMUN BOOST PRESSURE IS 13.23 PSI :(

I HOPE THAT THIS ARTICLE HELP YOU. :)
 
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