when starting it backfires through the carburetor, then runs rough,did a tuneup plugs and wires helped for a while, could it be the distributor shaft?
92 should be injected not carbed unless someone has been messing with it, double check the cap and rotor, could be a carbon track, recheck the base timing, as this is an OBD1 system it is still adjustable, check timing chain slop, if it is over 6 degrees then a timing chain set is recommended, get the codes pulled, write then down then repost here and we will try to help you along further.
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