Review on GTC GTC505 Engine Ignition Analyzer: Revolutionizing Engine Diagnosis and Performance by Patrick Cooney

I have a '94 Corvette with a crappy OptiSpark distributor on the front of the engine under the water pump. Some plugs are also difficult to reach. I've had cylinder misfires and the old school method of pulling a spark plug wire out of the distributor is impractical with the OptiSpark. I've only got less than a thousand miles with new wires and spark plugs. After receiving the device from General Technologies, I read the instructions while it was charging. I went to the shop, started the Vetta and started testing. In less than 3 minutes I realized which 7 cylinders were working and that the problem was in the second cylinder. Pulled the plug, visual inspection revealed nothing. I went ahead and replaced that plug with a new one and Bingo Baby! Smooth as glass and no need to change the other 7 connectors, saved me $50 in parts and 2 hours of labor.