golf5 1.6fsi throttle overrun
When driving my golf there is a massive delay between letting go of the gas pedal and the revs starting to drop. It's been getting worse to the point now where there's a delay of up to 4 seconds.
It makes driving the car really hard work. Every change up a gear I have to let go of the accelerator 4s before I put the clutch down otherwise it revs up.
I've looked at the throttle while someone else pushes the pedal and there doesn't seem to be any delay between lifting off and the throttle closing (it's drive by wire). I've had the throttle body off and cleaned all the oily carbon out of it and its made no difference.
Any ideas what could be the problem? Something bleeding air into the intake? EGR maybe?