I had throttle hang after taking off the throttle body, replacing the shaft seals and reinstalling everything... did a few pulls to verify the throttle hang. Pulled the throttle body back off and a tiny drop of anti freeze from the coolant lines had gotten down into the IAC chamber. Completely cleaned the throttle body, reassembled it and did the coolant bypass and I have had no other problems.

 

Mine does it aswell but it may hang a bit below 4000rpm

 

I am having mil.spec build my TB after a bit. While the piping is off for the FMIC, I am going to clean it. But I am pretty sure it is not mechanically related. As this entire thread states.

 

Early last week I reflashed my ECU with the P0300 disable that I found here because I was tired of seeing the damn CEL on for it. I've played around with the ECU and XML files for the last few years and reflashed etc plenty of times and knew this was easy, you are changingg a bit from 1 to 0 in one of the Periphery tables. That is all I did, hit the minus sign, saved, reflashed. Within a day I had throttle hang. I was getting pissed, I had throttle hang when I bought the car 2.5 years ago and eventually I never saw the issue again for about the last 2 years or so. I couldn't figure out what happened. I decided to reflash my car back to the old ROM taking out the P0300 disable and the throttle hang is gone again. I thought it was a fluke so I flashed back my P0300 disable flash and took it for a drive...throttle hang back. I pulled over and flashed it again, it was gone again. I can get the hang to happen 99% of the time in first gear at a constant pedal pressure and at about 6k if I engage the clutch and let off the gas the RPM's rise about 400-800 when it hangs/over revs.

Like I said, could this be a fluke? I'm on the 96940011 ROM also.