NefMoto

I have a '99 A4 with an ATW motor running ME7.5 (CM box with CH bin), VVT, SAI and cat diagnosis coded out, AWM MAF and injectors. Still using the ATW throttle body, haven't checked if it's different from AWM.

I feel like my throttle response isn't as good as it should be and I'm experiencing some rev hang on upshifts. These problems only start to really appear once the car's warmed up, but very rarely happen when cold or don't happen when warm, if that makes sense. My clutch switch works fine, I get much worse rev hang with it unplugged. When I had my throttle body out a few days ago I noticed that the throttle plate doesn't return to idle cleanly after opening it by hand, it bounces off the stop once or twice before settling closed. Is this normal? Today I logged requested vs actual throttle position and noticed that the TB can't keep up when I rev match downshift, the deviation at its highest was around 50%-75% throttle angle. The spikes were only 2-3 samples long at most, with the really high values only lasting 1 sample (20 samples/sec). Does that seem right? I also noticed that there was a lot of oscillation when the throttle angle changes, generally below 10% but spiking up to 20% at times. I'll post a log when I do a proper one, this one was a quick test and I didn't get as much data as I'd like.

Is this a recent thing, or has it always been like this?  The oscillation is not normal.  Usually elec. throttle is quite precise.

Is the throttle chasing MAF readings maybe?

I swapped the motor in about 1.5 years ago, it's always been this way. Since the car used to be a DBC v6 I have nothing to compare it against. I doubt it's MAF related, actual throttle angle is perfectly in line with requested 99% of the time, it falls behind on quick changes and oscillates on any throttle changes no matter how gradual.

Replace it. They are dirt cheap :)

So you think it's bad eh? That's a shame because I just painted it a few days ago.

replace it. like aardq said, the oscillation is not normal. it should be pretty dead on.

Will do, thanks for the definitive answer. Just so I'm sure, here's a screencap of a bit of the log I did last night. Blue line is actual, orange-red is requested, gray is (requested - actual), and yellow is the clutch switch as a reference. The first part I think is from me putting it into neutral while moving and later revving it up and popping it into a lower gear, the last 2 spikes are rev-matched downshifts.