I think it might be Deezee that gets the prize biscuit - possibly even a chocolate hob nob. Before we all get too excited let me explain.
In going thorough all the suggestions I have pretty much ruled out an air leak or a sensor problem. The wiring to the ISCV checks out but if I disconnect it the problem remains the same.
Having had a quick look at the Haynes manual it says that the iscv allows air to bypass the throttle to set and maintain tickover.
So what I did was to disconnect the pipe that comes from the iscv at the manifold end. I stuck my finger over the stub pipe and tried to start the car, it would not idle at all - it just died. So I blocked off most of the hole and tried again. I found I could control the idle speed by just allowing a small amount of air in - basically simulating what the ISCV does. I could quite easily set the tickover at about 850 and keep it there.
I therefore believe that it is the valve that is working in a sub optimal fashion or to put it another way - buggered.
Does this sound sensible? Does anybody have one they don't need so I can prove my theory? Is there a God? Actually, forget that last one, I'm too tired.....
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