Difficult To Start Ordinarily

Check fuel quality.
Check spark plugs.
Check idle speed control valve. See SYSTEM/COMP TESTS article.
Check water temperature sensor circuit. See CODE 22 in TESTS W/CODES article.
Check EGR system. See SYSTEM/COMP TESTS article.
Check fuel pump and fuel pressure regulator. See SYSTEM/COMP TESTS article.
Check fuel lines for damage.
Check RPM signal circuit. See CODE 12 in TESTS W/CODES article.
Check ignition circuit. See CODE 14 in TESTS W/CODES article.
Check intake air temperature sensor circuit. See CODE 24 in TESTS W/CODES article.
Check distributor.
Check fuel injectors. See SYSTEM/COMP TESTS article.
Check cold start system. See SYSTEM/COMP TESTS article.
Check ECU. See SYSTEM/COMP TESTS article.