Time for an update. Put a scope on the ecu and check all the sensors were working correctly which they were and all continuity is good. Now the rev counter has stopped working all together and it hasnt miss fired once. I have taken the rev counter out and tested it using a signal generator and it worked fine. Also tried different ign amps aswell and no change.
Because its got the MSD wasted spark fitted, the green wire that would trigger the rev counter from the coil is no longer connected and hasnt been for some time. Where does the rev counter now get its signal/pulse from? I just cant get my head around it, its probably so simple Im overlooking it.

Dangerous Brian - Im not sure if the suppressor is still part of my circuit as the wasted spark is fitted.