I have the following electrical problem with my 69 z28. It has electronic ignition (Mallory power cell, coil and distributor). When I turn the engine over I get a spark either out of the coil wire or spark plug wires, but only initially (i.e. one spark). If I continue turning over the engine, no more spark until I let off on the ignition switch and bingo one more spark jump across. Could this be the ignition switch? Does anyone have any thoughts? It doesn't appear to be the coil, distributor or power cell. One other note, a pack rat gnawed some of the wires, but I believe they have all been replaced, but perhaps I missed one and its still shorting out somehow.