Hello again just a quick update, had it recovered to main dealer who read codes. Turned out to be CPS breaking down when getting hot. That was going to be next point of call, but it started within half revolution with no misfires or uneven running. Thanks for all your input,help and advice. Also we may have averted the RCM problem. So another Crossfire will be back on road tomorrow.Can now get back to sorting out my 73 Mach 1 for the upcoming rally in France. So once again thanks you guys cheers mickmatt