Pontiac Repair: 1993 Pontiac Grand Am 4 cylinder, fuel mixture, data sensor

Question
I start it up and it runs for about 5 minutes then it starts smoking black out of the muffler and then it just dies. I try starting it again and it just cranks but dont start. Could u tell me if you know what the problem is.

Answer
Hi David.
The black smoke out the exhaust would indicate an overly rich condition. It can be from a lot of things. A engine data sensor that's giving a bad signal to the computer. A sticking open fuel injector. A restricted return line for the fuel system back to the tank. Has any service engine soon lamp come on? You could have a bad ground connection going to the engine computer and that will make the sensors particularly the oxygen sensor read wrong and make the engine computer richen up the fuel mixture. Good luck :)