Thanks for the replies ... I am convinced that it is an ignition problem as it does run (sort of) on #4 which comes out with no gas fouling (the one that it runs on) ... the other 3 are soaking wet. I have checked the air deflector plate and it seems free ... I have also disconnected the starting injector (I think that is the one on it's own with a electrical plug connected to it) All these made no difference ... I have checked the spark on each cylinder by a grounded plug and there is a spark on each ... the # 3 was a bit stronger than the rest ... but there is no way of knowing how they behave in the combustion chambers. I shall try and find a second hand Bosch dizzy, which won't be too easy here in Spain as they usually want as much as a new part for some second hand bit.
I was going to try another coil, but I only have coils for normal V8s ... they are the same size (and probably voltage) as the XR3i but the on on it says electronic ignition coil ... is there a difference ?
I have been looking into the operation of the MFI system as I just couldn't figure out how it worked ... quite a simple system really ... compared to EFI and associated ECUs etc. Makes a change from carbs for me lol.
On another subject ... is there anyone who sells the 3 rubber insulator mounts for the fuel pump cage ?