Cheers for the input, i fixed it last night, i do believe it was the 3rd multiplug- (one closet to passenger side), but i cleaned the middle one just to be sure, didn't have time to do the last one though but it seems ok as there are no other faults anyway. There are 3 multiplugs that are on the bulkhead, the BIG main ones, it was those i meant, sorry for any confusion.
The ecu must have been getting duff readings as my secs is wired into the loom there, and it was displaying double RPM which is also what the ECU would have seen, it's ok now though.
CHEERS!!!!