Gus

Ok, I know this is a 964 Forum - but you guys are great with issues and I need help. Have a problem with a 74 MGB that I am helping my son work on. The car will not start with the coil wire plugged all the way into the distributor cap. But, if you pull the coil wire out of the distributor cap until you can see the spark arch ( it gets stronger as you pull the lead out) the engine will start. Have replaced coil, distributor cap and rotor button - but still have same issue. Car has a CRANE XR 700 light pulse point replacement.
Anyone have any ideas- thanks

Babalouie

Might be a long shot but can you try checking the low tension power supply to the coil?

Foolproof way to do it, would be to hardwire it temporarily to the battery. If it suddenly works 100%, then you probably have a wiring/connector issue on the coil power wire (probably something to do with the key barrel or something)

cwrm4

Have you checked that the ballast resistor is in good shape and correct for the Crane ignition (if it needs one)? It could be when the coil wire is not connected to the distributor the current through the coil is reduced, whereas when it is connected the current is too high and the coil is failing? Just throwing out ideas...