Engine hesitate at times

I dont know whats wrong but at times car is hesitate to respond after I have come to a stop at traffic lights or junctions.

The problem doesnt appear nor do I know when it will happen. When it does happen I try to accelerate in D, S, R and even N without the revs moving. Revs do not move no matter what input until it decides to move again. Problem only last for around 5secs but I find it very dangerous at junctions once I've pulled out car cease to respond!

I tried to vagcom the car but can only get a partial reading. Which module should I scan if I do get the vagcom to work again. Could it be the CVT ECU (new ecu installed) playing up or the electronic throttle?

All comments welcomed:1zhelp:

Many thanks!

J