hi all .
I have a Canter a 2004 model 3.9 diesel.
The problem is that when its revs to approx 2000 rpm or above and the throttle is realesed
the revs take appox 20 seconds to drop to normal idle.

Under 2000 revs all seems to operate ok.

Have replaced throttle sensor (fly by wire)and have done various checks ie visual wiring etc and checked for restrictions in air pipes etc .

All help and ideas will be much appreciated .

Regards Todd