Testarossa wiring expert HELP -start issue

This can be a symptom of the tachometric relay (F PN = 124717) not working correctly. It controls the fuel pump relays and has two modes -- A) During cranking (key Pos III), it senses the signal going to the starter motor solenoid. If present, the tachometic relay closes = closes the fuel pump relays = runs the fuel pumps. B) During engine running (key Pos II), it senses the 7/12 coil firing = closes the fuel pump relays = runs the fuel pumps.

First thing to do is confirm/deny spark on the 7/12 bank during starter motor cranking. A search on "0280230006" and/or "tachometric relay" should get you some prior threads.

 

This is what has to be fixed (there was no need to try a different tachometic relay).

Since you have a "spare" TR -- swap over the 7-12 coil + power module assembly and retest for 7-12 spark (although, if one of those is the problem, it would start and run). If your two TR have different style coil connections, you can also swap the 7-12 coil+power module with the 1-6 coil+power module on the same TR and retest (it will only run on one bank, but it should stay running -- and it's helpful to label things, like with a piece of masking tape to keep track of who's who, and who was where originally). If it does run on the 7-12 bank after the swap, I'd put a 97% probability on the original 7-12 power module being bad, a 2% chance on the original 7-12 coil being bad, and a 1% chance of it being a bad wiring connection problem -- but you should be able to rule individual components in or out by mixing-matching them around.

 

Not sure about that, but I will claim to be know how TR work thru many painful experiences

Still sending you much positive mojo for your project - if TR are relatively rare, a spyder TR is a unicorn!