Black Gas Cloud

1990 Grand Wagoneer. At startup, it sputters and jerks, and eminates a noxious, black cloud. It leaves a black stain on the snow. If I keep the throttle depressed, it runs very roughly until smoothing out somewhat. If left alone it will die. I live in Fairbanks, and it gets -50 degrees here. The Jeep is carburated, but the mechanic can "find nothing wrong". Any assistance, especially from a colder climate, would be greatly appreciated. Thank You.

black cloud is too much fuel. with the very cold temps the choke is stuck closed or never opens at all. starving the engine for air. check the choke linkage for freedom ov movement and also check the air cleaner housing snorkle to see if the exhaust heat plumbing is functioning. also, make sure ur oil is of a lo viscosity. 5w30 or less.

also, try this place too
www.off-road.com/~ifsja

c my attachment too