TTinCT

Could be a pre-cursor to engine speed sensor failing....

RSole

Had the same problem with my 2001 (A4) Jetta TDI. I researched that it could be the anti shudder valve (which blocks off air to the engine to stop violent shaking when the engine is commanded to stop) or it was the immobilization system. The immo icon showed on the dash indicating that it was not a legit key in the ignition switch. I was able to drive home after disconnecting the battery cable from the battery and shorting out the pos and neg cables for 20 seconds. Hopefully this reset whatever was unset in the car's computer. Every couple of weeks my engine would crank and then die after one second, then after several tries it would run normally. This problem may return for me, if so, I do not know what the solution is. A new ECU? Hope this helps.

NJAldwin

The same happened to me - after having it refuse to start for me on several occasions, it died on me at a red light (how embarrassing). It turned out that there was a problem with the crank sensor producing an incorrect reading. You should probably get it looked at soon.

McGyverGuy

I was having the same problem with my 2001 1.8, and wound up chasing a vaccuum leak (oil dipstick tube was cracked, and replaced the 'air flow sensor?') Since the new parts went in there hasn't been a failure to start, AND I seem to have corrected another (unknown to me) problem that gave me back what seems to be about 30-40% of the power I didn't know that I have been driving without! Apparently the air flow controller also has "yes/no" control over the turbo kicking in.
Not being a mechanic, I hope this helps.....

dodge8man7

i have a problem that sounds alomst the same but ithink its something elnce my one tt quattro if it has less then a 1/4 tank some times it will start then die rite away it only does it when it is low on gas and it does it with both keys. we where haveing other problems like 4 months ago and i replace fuel filter and fuel regulator and the audi shop replaced mass air flow and coolent temp sensor then those problems went a way. keeping the car full on gas for know tell i can get more ideals to see if im on the rite track.

J. Patterson

Still sounds like an immobilizer issue. Have you tried other keys? One can fail without affecting others. You have to take all the keys to the dealer with the car in order to re sync them. There is a yellow key icon in the dash cluster that illuminates if the immobilizer is active. As to other possibilities there is an engine speed sensor on the front of the block that can cause intermittant start no start issues. It would be rare for it to give a -start run 5 seconds shut down consistently -- effect though. I suspect an immobilizer issue. either a failed key, or a bad cluster if multiple keys are affected.

Peter Badore

Have you scanned the TT with VAG-COM? Maybe an intermittent problem with the crankshaft position sensor or the ignition switch?