1986 300E wont stay running smell rich

[JerryWagner]

My 1986 300E will die in the middle of the street and not start for 5-10 minutes and then will run for 5 minutes and die, when trying to start it sounds like detonation and wont start, wait a while and it runs normal and then stops dead, I do notice that there is black carbon soot on the back bumper where the tail pipe is and it smell like it's running very rich, it was towed today, anyone know what this could be ? it's getting a good flow of gas to the pressure regulator I suspect an O2 sensor or the pressure regulator, does this car have a computer ? HELP