I have an intermittent part throttle miss on my twinspark, I have checked the ignition system generally to no avail, swapped out injectors and all sorts. It happens usually when I'm cruising along for a way with the throttle reasonably constant, then accellerate. It's a constant, stuttering misfire, if I hold the throttle steady when it's missing it carries on, if I let off then press the throttle again it goes. It seemed to me to be when theres a substantial change in vacuum, so Ive checked the vacuum hoses and started to look to the AFM, but cleaning the track inside etc has not changed things at all. I have tried with 2 different fuel pressure regulators, as well as using 2 different ECUs and I'm running out of ideas. Not checked compression yet, but I dont lose any fluids or burn oil at all, so I'm confident that is OK.