Newbie question, 89 Allante

I have a problem with my 89 Allante, that has me baffled, The problem started about a year ago. The car would cut off while
driving, I was always able to get it cranked if I waited a few seconds. Now the car does not always crank when I want to drive
it, other times it will crank and I drive to my destination but upon wanting to return home the car will not crank. No codes will
appear in diagnostics.

The catalytic converter stopped up and the replacement didn't have the correct inlet and outlet diameters so I cleaned out the
old one and have it installed. The idle speed started fluctuating, I have cleaned the throttle body, replaced the distributor, the
idle speed control motor, the throttle position sensor and cleaned most of the connectors. The idle still fluctuates some what. I
have followed the procedures in the service manual for setting idle and tps. I really enjoy this car when it behaves!
Any suggestions on my next move?

Thanks, Larry