My old 94 used to sputter really REALLY bad when it was cold. Spit out black smoke though! Turned out to be the EGR solenoid. Not the actual valve, but the part that has a electric plug and vacum hose hooked to it going to the EGR valve. It was shot and was causing a vacum leak, and untill the engine temp is up, the ODB1 computer doesnt kick in and correct the problem. you might try having that solenoid checked out.