I am getting a very weak yellow intermitent spark at the coil terminal. It is a new coil. Tested primary and secondary resistance and it is within specs. Also tested supply voltage to the coil and it is also correct. Any clue as to what to look for next?

 

Make sure the Coil is grounded. This sounds just like what another poster had and after replacing everything it turned out to be the Ignition Coil was not grounded.

Also make sure your Ignition Ground is good, for the Ignition System the ground is inside of the Distributor.

Do not forget to check that small black wire at the Neg. Post of the Battery, it will cause all sorts of problems.

 

When you refer to the ground being inside the distributor do you mean where the 3 spade connection is made when installing the ignition module? Thanks

 

Yes, one of those three connectors is the only ground your Ignition (TFI module) has.