A3 1.8T Misfire when engine hot

Hello,
I wonder if anyone can help. I have a 97 A3 1.8T sport. After I have driven the car for approx 20 mins at motor way cruising speed the engine starts to misfire, it gets so bad I have to stop the car and
let it cool down. However the story doesn't stop there, if the outside temperature is below 2 degrees the car rarely misfires.
I took it to my local Audi deal, they connected it to their computer and told me that it required a new throttle body. So they duely fitted it, this did not fix the problem. That was 3 months ago, to date they have not been able to diagnose what is wrong, as every time it happens and I take it to the garage, one, the car behaves and two, there are no error codes stored in the computer.
Help!! Any ideas?? I thought about replacing the coil packs, what do you think?
Regards
David.
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Do you drive it to the garage/dealer WHEN the problem is occuring?
later, dave Reminder........ Before you criticize someone, you should walk a mile in their shoes. That way, when you criticize them, you are a mile away from them, and you have their shoes. Frieda Norris
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snipped-for-privacy@aol.comANTISPAM (dave) wrote in message (David Styring)

I have never been able to get it to the garage when the problem has occured, as i have been half way down the country stuck on the A1. the best i have been able to do is get it there the next day, therefore the car has had one engine start since the problem occured, I have been told that the information stored in the cars computer covers the last 7 starts. However they have still not been able to find it. I just collected the car yesterday from my local dealer, after a weekend of travle and misfire it was booked in again, and guess what..nothing wrong! any thoughts?
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It could be a low fuel pressure problem or ignition problem or possibly vacuum problem. Have you done an engine service, esp the air filter and fuel filter? Are there any screens in front of the air filter box that might be trapping debris and restricting clean air coming into the box?
Well you could buy the vag-com tool at http://ross-tech.com/vag-com/index.html and do some scanning of codes and examine measuring blocks yourself. That might give you the ability to KNOW what is wrong or what is not wrong.
just a suggestion! :-) later, dave Reminder........ Before you criticize someone, you should walk a mile in their shoes. That way, when you criticize them, you are a mile away from them, and you have their shoes. Frieda Norris
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snipped-for-privacy@aol.comANTISPAM (dave) wrote in message

Thanks Dave! have just purchased the tool, will let you know what i find out in the coming weeks.
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