201-A4

Lets say I am cruising around in 4th or 5th gear and I mash the throttle at 2k, the motor will rev smoothly until 3k. When the motor reaches 3k, it lets out a popping noise once or twice, then stumbles up to 3400 rpm. After about 3500 everything is fine and the car pulls hard up to redline.

Last week I drove around with a trusted tech who was using a vag to check the specs, as the stumble occurred. He stated that the readings from the MAF, 02 and injectors all looked fine. I'm guessing he was monitoring blocks 002, 003, 031. He diagnosed the popping as a backfire into the intake. He thought it could be caused by the throttle body malfunctioning in the 3000-3400 rev range. We did not get to try out a new throttle body because I had to go back to school.

I can not say for sure whether or not I had this problem pre-T28, but never the less it is very odd and I would like to correct it as soon as possible.

Has anyone had a problem similar to this?

Is his diagnosis accurate? If so, it the throttle body the culprit?

TIA

201-A4

I dont have any graphs of the logs, but I will try to get some later this week.

nospek3

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201-A4

The car really bucks when the pop occurs, would that be a symptom of pinging?

nospek3

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201-A4

The tech was logging misfires as well. He didnt see anything out of the ordinary.

nospek3

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mau

I had similar problems like that at one point. It sounds like a misfire. Does it show any fault codes? what plug are you running? how are your coilpacks?

Mau