Has anyone an idea for a golf 4 AEH 1.6 litre motor 1999 model will idle perfectly in nuetral/park until light throttle lifts rpm to 1200 and then the engine hunts to 1500 hits overun and drops then revs again. Throttle angle at idle around 4 but when hunting it remains at 7 or so, changed throttle body, no difference, measuring block 2 shows motor in and out of decel and the only way to steady idle a/c on select gear and idle settles until loads turned off and throttle openened again, O2 sensor cycling, only fault is "idle stabilisation lower limit" power steer switch activates correctly, the idle hunts the same with air mass plug disconnected, no air leaks apparent all measuring blocks read within tolerances. Please any ideas?