Hi guys. Could really use some help, I am stumped!Here's the specs: 1985 Ford f150 XLT Lariat 5.0L V8 302 engine 2 BBL Carb VIN F seriesTruck starts perfect, purrs like a kitten. Once it reaches operating temp it stalls out, shuts down.I ran the codes and get only one - code 31 There are...