Versus_Creations, I have tried it with idle valve unplugged and plugged in and is still the same. I have also tried unplugging TPS which also had no effect.
gup, I have had the throttle housing off to try a later one to see if I could avoid using a spacer plate between the 2 halves of the inlet manifold so will check this as this could provide the amount of air needed to demand enough fuel to run at max. I am also going to check the MAP sensor, its connections and pipework as if this is not working the ecu will use throttle position sensor to determine the amount of fuel being put in by injectors by providing a value. which could be idle, part load or full load.

Thanks for your replies, I will let you know how I get on.

K