So I've been having an intermittent issue for the better part of the last 2 years on my 87 GT, and I've been stuck scratching my head. Periodically, the car will stall and will not re-start unless I disconnect the negative battery terminal and let the car sit for a few minutes. When it stalls and I try to re-start it, the engine turns over but doesn't fire up. If I try to re-start it too quickly, it seems to vapor lock, resulting in my having to have it sit for longer. It doesn't happen all the time, but it's just enough to be a pain in my ass, as it happens at the most inconvenient of times, and almost never in my driveway or garage. I've replaced the fuel filter, thinking that was the culprit. I've replaced the fuel pump, thinking that was the culprit. Neither have solved the problem. About 7 or 8 months before this issue came about, I replaced the ignition module by the distributor with a supposed genuine Motorcraft part (I say "supposed" because I've heard that it's basically Chinesium with a Motorcraft logo on it). Could that be the cause?