Civic 1500
- Connect tachometer to engine and vacuum gauge to vacuum advance hose, then start engine. Vacuum should be present at idle on Federal engines with manual transmission, and vacuum should be present at 3500 RPM on all other engines.
- If no vacuum is present, check all hoses to distributor for blockage or leaks. Connect a hand vacuum pump to distributor, start engine, and pull 8 in. (200 mm) Hg vacuum. Timing should advance and hold. If not, replace vacuum diaphragm.