Some of these ignition systems use a resistance wire in the "run" circuit to
limit coil current. Some use a resistance coil. Make sure you have the right
components for your ignition setup.

Bill
"dave" wrote in message
om...
Dave,
The tach jumping around probably indicates a problem with the primary
ignition - the 12 volt parts. That would include battery, key switch,
coil, distributer pickup and electronics, and wires in between.
The cap and rotor corrosion may indicate either moisture or other
contaminates in the distributor, or excessive resistance between the
rotor and the spark plugs.
Check the voltage at the coil while running.
Have the coil checked on a scope, they can fail intermittently.
The moisture/contaminates may be coming up though the distributor shaft
housing because of excessive crankcase pressure. Check the engine
breathers and PCV system.
Al


Thanks. It sounds like you think like me. I have been through every
wire I can find, have disassembled and cleaned the ignition switch,
checked everything I can think of for correct continuity and/or
resistance. I put in a new MSD distributor and plug wires are new. I
have not checked the voltage at the coil while running. Coil is
original. I did just find on the coil that the resistance for the
secondary wiring tests at 7500 ohms, while the manual states
9500-11000. I'm not sure that means anything, though. I guess I
could throw on a new coil. Thanks again.