Just for your info...I posted a while ago that our Golf 1.8T (AUQ) had cold running problems. Lumpy and jerky when initially setting off etc.
At the weekend I finally got round to doing some tinkering.
1) I disconnected the MAF and went for a drive, with the car cold. Car was smoother. (So we may need to change the MAF)
2) Decided to do some cleaning. Disconnected the intake pipe to throttle body. Squirted some Wynns Carb/Injection Cleaner in there, and wiped out the oil residue. It was pretty clean to be honest.
3) With intake pipe still disconnected. Switched ignition on, but DID NOT start the car. Put something heavy on throttle peddle to open up the TB butterfly valve a bit. Squirted some more Wynns in. Waited for it to dribble out and wiped inside. Being careful not to touch the TB butterfly valve - didn't want to damage the electronic actuators etc. Then switched off the ignition, wiped around again, and then reconnected the intake pipe.
4) Disconnected DV (standard 710N). Noticed it was quite oily. So squirted some Wynns in there too. What the hell. Let the oily gunk drain out and let it dry off.
5) Re-fitted DV.
6) Started car, and let the intake temps get up to about 80 degC. Then stopped the car.
7) Disconnected turbo intake hose from MAF. Started engine. Squirted 1 shot of Wynns into the intake and waited for around 30 seconds. Repeated this about 5 times.
8) Reconnected intake hose to MAF
9) Removed MAF sensor with Torx Security socket (TX25, 5 star pointed). Cleaned MAF with IPA solvent. Let it dry a bit. And then reconnected.
10) Cleared MAF fault code (because I had run the car with it disconnected)
11) Started car and let coolant temp get back to about 80 degC
12) Stopped car. Did a Throttle Body Alignment.
So far, when driving the car from cold it has been better. I'll let you know if the problem returns.
AL