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On Monday I drove my car (1998 A4 1.8T) back from the shop after getting an alignment. It drove fine, as it has for months. A few hours later that evening, I went to drive the car. It started, and immediately shut off like in the video. Since then, I have been unable to figure out what’s going on.
I am able to keep the car running if I continually press the gas pedal over and over. I cannot just hold the gas pedal to keep it at 2k or 3k RPMs. If I do that, the car dies. I have to keep revving it or it shuts off. Right before the engine cuts out it will rev up to around 800-1000 RPMs. (This can be seen in the video at around 20 seconds in.)
I had a similar problem last year and it turned out to be a faulty mass air flow sensor. I was able to test it this time with a good MAF and the problem persists. I also tried running it with the MAF unplugged and have the same problem.
The fuel pump can be heard when you flip the ignition on. I have tested for spark and it is good. There are no CEL codes. I also have a VAG COM scanner and there are no codes with that either.
Really at a loss for what to do next, and it’s not a great time financially for me to just throw parts at it.
Video: https://drive.google.com/file/d/0B0SQiUinnuqJazRTM3FiR1ZZd2c/view?usp=sharing
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Check the engine coolant temp sensor. with a cold engine it should read close to the ambient air temp sensor. If you see -40 or a any other unreasonable number than their is a problem with the coolant temp sensor circuit. If you have a large vacuum leak this could also create your concern as well. Aslo if the computer has lost its base throttle blade position it could create this issue.
How would I check what temperature the coolant temp sensor is receiving?
I don’t think it’s a vacuum leak. I don’t hear any hissing or unusual noises, and don’t see anything out of the ordinary with all of the hoses.
you said you have a vag com scanner. You should be able to check some scan data. their should be a PID for engine coolant temp. it may also give you voltage. if so high voltage would indicate a cold so 5V would be -40
My scanner does allow me to scan for VW/Audi trouble codes (there are none in this case) but it is not actually VAG COM. It just reads the same codes as VAG COM, as well as OBD codes. I can’t do things like view engine coolant temp.
well then you will need a scanner that can view data. Coolant temp data is an OBD 2 mandated pid and it will be their with any scanner that can show live data. Is the security light flashing. Also sometimes on European cars you may try disconnecting the battery and touching the two cables together to do a hard reset and then reconnect. you would be surprised how many times this has fixed weird things like that for me.
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