I'm going to look at a 1994 Manual w. 79k on it tomorrow. Owner states that three times the car died on him while at speed. Does it when it is hot, and does it when it is just started up and driving away from his house. Once driving cross country from Arizona to Minnesoata. Appears original and un modified in pics. He parked it and is now just selling it on. I could make a ton of guesses, but I'm hoping there is something that it's a known issue and an easy fix! Any ideas appreciated.

Past C4 Crossfire owner, hoping to move to something a little newer for a track day car.

 

check the relay, top passenger side of the engine, that acts like a thermocouple, opens up when it gets hot, it feeds the voltage to the opti-spark

 

Welcome to the forum.

Check the fuel pressure with both the engine on and with the engine off but the key on.