Spark plugs, spark plug wires, distributor cap/rotor, fuel filter, tranny fluid, and air filter. That stuff can usually lead to a crappy running car. I'd try the plugs first if I were you since they should be changed every 30k on the B18B1 anyways. You are going to want to check on that timing belt too. If it hasn't been changed yet you are running on borrowed time.

And check the valve clearance.