Audi TT starting issue
 

Hello - Owner of a 2000 tt quattro - The car runs well however about every 4 months or so the car will not start generally when it has been driven frequently during the day. The EPC light stays on and the car turns over, idle jumps then dies. If the EPC light on dash goes out the car starts fine. Car spent 3 months at dealership, they couldn't figure it out - 4 months at independent Audi shop - changed cluster, fuel pump etc. didn't help...has anyone else experienced this??? Thanks

Sounds like it could be a MAF (Mass Air Flow Sensor) issue. Unplug it and see if the car starts and runs. The computer (ECU) will compensate for the loss of that sensor and make it run. It also could be a crank or cam position sensor. It the ECU cannot determine either one is spinning and how fast, it won't run either. The EPC light just means that the computer detects something wrong with one of the electronic sensors. Can you get any codes from the OBD?

You can try to clean the MAF sensor (easy to remove) using a MAF sensors cleaner spray that you can get at any Automotive Store (Autozone, Advance Auto). They cost about $200 regardless of what vehicle it is. I know Audi uses the same unit for quite a few models.

Also, what type of air filter are you using on the car. If you're using a K&N filter, it's possible that some oil residue from the filter media has gotten on the very fine heater element in the sensor. It this element has ANY contamination on it, it will give erroneous readings to the ECU and trip the EPC light and possibly the Check Engine light.

HTH,
Dave

Dave thank you I'll give it a try - this thing is making me nuts. The error code the dealer reads has to do with the immobilizer but for whatever reason they ruled that out. Again Thank You