Originally Posted by tabetha

Whoever advised you about it could be the phase or crank sensor, would be better off, not advising anyone of anything.
It sounds like a sticky ISCV, quite normal, just needs a good clean with carb cleaner then spraying with silicone to keep nicely lubed.
This is the sensor on top of the throttle housing with a two pin plug going to it and held on with a metal plate around it's base a with two screws.
Failing that could be a sticky throttle cable.
tabetha