No Complete Combustion

Check for vacuum leaks.
Check fuel system circuit. See FUEL SYSTEM CIRCUIT chart in I - SYS/COMP TESTS article in the ENGINE PERFORMANCE Section.
Check idle speed control valve circuit. See IDLE CONTROL SYSTEM in I - SYS/COMP TESTS article in the ENGINE PERFORMANCE Section.
Check ignition coil.
Check distributor and spark plugs.
Check airflow meter circuit. See CODE 31 in TESTS W/CODES article in the ENGINE PERFORMANCE Section.
Check ignition signal circuit. See IGNITION CHECKS in BASIC TESTING article in the ENGINE PERFORMANCE Section.
Check engine compression.
Check water temperature sensor circuit. See CODE 22 in TESTS W/CODES article in the ENGINE PERFORMANCE Section.
Check injector circuit. See INJECTOR CIRCUIT chart in I - SYS/COMP TESTS article in the ENGINE PERFORMANCE Section.
Check cold start injector circuit. See COLD START INJECTOR CIRCUIT chart in I - SYS/COMP TESTS article in the ENGINE PERFORMANCE Section.
Check valve clearance, valve timing and timing belt.
Check piston rings.
Check ECU.