Thanks for all the replies,

Tony & Michael I have had plug problems before on Fiats so I changed plugs and leads today fault still there.

Gwyn It has a idle control valve like the Vaxhalls but it checks out OK and like the TPS is non movable and is pressed into the throttle body.

John The crank and cam sensors are giving good scope waveforms.

Tony What I cant understand is when revving up and forcing the fault the mil light comes on but nothing is stored in the ecu memory. I disconnected a few of the sensors to check ecu for picking up faults and they all showed up.

Keith This model has a map sensor on the manifold next to the throttle body.

The symptoms are exactly like a corsa with a jammed open throttle actuator holding the butterfly open and fooling the ecu into thinking its on over run which switches the fuel injectors momentarily off. My thoughts are "a" tps which is pressed into the throttle body and at .6v may be just over the closed limit "b" the ecu may be at fault.

Barry