Preliminary Checks

Check for intake air leaks. Check ignition timing. See BASIC TESTING article.

• Check EGR operation. See SYSTEM/COMPONENT TESTS article.
• Check EGR control solenoid valve. See SYSTEM/COMPONENT TESTS article.
• Check vacuum hoses for leakage or misrouting. See VACUUM DIAGRAMS article.
• Check spark plugs for evidence of excessive oil consumption.