this w'end i:
replaced the dizzy cap and rotor arm, that got rid of the kangaroo juice when setting off (van still idling at 1500)
stripped the throttle body and cleaned everything up with degreaser & re-assembled(brought revs down to 1100, still no kangaroo juice)
looked at all the breather pipes and it turned out a previous owner had used the piping you use in a fish tank(see through green stuff ) from the fuel regulator valve(where the pipes to the injectors comes from), back into a housing beneath the valve. rI replced this with the correct diameter/type of piping and this brought the revs back down to about 750/800 & the stutter when off the gas pedal has now disappeared.
i looked at the connector on the back of the thermostat housing and whilst trying to pull it off to inspect, managed to pull the temp sensor out and drop half my coolant, turns out there should be a clip holding this in and an O-ring around the sensor to seal it, if this happens to you, remember to look/feel up the pipe, as the O-ring sat up there and hadn't come out...
All sorted now and thanks alot for your answers
Happy dayz
Bradders
