Hi all it's been a while.
I've just had my mk 4 in for it's mot passed with no advisorys
But on the way back it's developed a fault where it's drives fine then won't rev just ticks over turn it off start it up its fine again then after a few miles does it again. The only thing that has been done to it is a new cold start fitted that seems to be when the trouble started.
Diesel must be getting through for it to tick over but I can't understand why it won't rev even pulling it manually timing belt is only a year old and it all locks up in line with the pins.
Any advise would be great thanks in advance