I'm checking the spark from the ignition coil. While cranking there's no spark as soon as I stop cranking it shows one spark. Is that right? And then I'm getting no spark from the dizzy to leads. Brand new rotor button plugs and dizzy cap. Any ideas what this could be? Also I havnt changed leads could that be the problem? Thanks for your help!

Power transistor maybe NO SPARK VL COMMODORES System uses an LED crank angle sensor (CAS) within the distributor to generate a speed signal (360-degree for timing) and a position signal (120-degree signal) for the computer (ECU). The ECU then uses these 2 signals to generate a trigger to the power transistor (PT) bolted to the outside of the distributor. The PT uses this trigger to switch the -ve coil to ground to generate spark. On top of the distributor is a 4 pin harness plug - this is the crank angle sensor. With this plug removed test the voltage on each pin of the female harness plug against ground (engine earth/battery -ve) with the ignition on (KOEO). Should have 12v (battery volts from the EFI relay), earth (Ov), and on the remaining 2 pins - 5v on each (from ECU). Ensure the distributor shaft is turning during cranking - cam belt. With the engine cranking these 2 wires which had 5v on each are the important signals you are after - expect approx. 2.3v on one and 0.3v on the other. If the CAS has failed expect close to 5v OR close to 0.0v on one or both. If the signals are BOTH within 20% of specs., then Check the signal from the ECU to the PT (fawn wire onto PT). If ECU is generating the correct signal expect approx. 0.4v. If a greater voltage, then you have an earth problem. If 0.0v then the ECU is not outputting the signal - ECU failed. If correct signal but still no spark then the PT has failed to switch the coil (rare) or the coil has failed (common). To check the PT is switching the coil, use a normal test light from the +ve battery to the -ve coil (brown/red at PT). Your light should illuminate with KOF (ignition key off), and when the coil is switched to ground through the PT during cranking. If your test light flashes during cranking then PT is doing its job so coil has failed. If no flashing then PT has failed. Or if test light constantly lit, then PT has failed.

Thanks heaps mate. Appreciate it