Rough running again

[wizzer]

Hope you've all had great summer.
Some time ago I posted about the S running rough, I never really found the problem but it seemed to resolve it's self, until today. Bowling along the coast road close to home when she starts missing and losing power, pulled into a car park then she was really rough, missing, backfiring no power, just as though all the plug leads had been taken and muddled up. Turned the engine off, turn on starts as though nothing was wrong! What ever the problem is, it clears when the ignition is turned off.
Got home put the STAR tester on, no fault shown. Could it be a fault outside the parameters of the FCR? I have run out of ideas. Can anyone through any light on this problem

[glenrobbo]

Intermittant faults are always the hardest to pinpoint & you can never be sure you've actually cured it.
Have you given everything a good wiggle to try to reproduce the symptoms?

Hopefully somebody with greater knowledge will be along in a bit.