I would change Mr. miesk's answ from mom'n pop store to "big box stores" as AutoZone, PepBoys, etc have a code checker they bring out 2 ur car. OBD 1 is touch though (count blinkin lights).
I do the same as you Dlaw. Machine bearly used in summer (it is a woods vehicle used for income. I do not cut trees until the babies have left home as mature - birds, squirrel, fox, etc, etc). In "the ol daze" (pre-ETHO in the gas) I could come out'n start 'er right up. Now w/all the alcohol it evaps'n gums up the works (carb, lines, tank, etc). That;s a-lot wrk to clean so I run dry or put correct amt of stabilizer in (oz per gal) and run the vehicle till its upinda float bowl of the carb. By '90 it would B injectors or TB. U may hafta clean out ur fuel system. Lucky if it's bearly running as U can put some in tank now (I'd drain & start over?) and spray down the inside of the induction system as it runs. It can get drawn in (fuel sys cleaner) as it runs/U hold dwn an aresol button. U can hear it run better if it wrks as U do this...