my cosworth has developed a missfire for the first time under load at about 4000 rpm. so far have changed coil, cap, rotor arm, cps, phase sensor, ignition amp. checked & cleaned all connections & all the wiring multiplugs near the bulkhead have been removed & hard wired. only thing left are the leads which all appear ok but when I measured the resistance all were showing around 2ohms is this right?