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Accord and Prelude 1800 (Federal)

  1. Connect vacuum gauge to advance hose at distributor. Start engine; vacuum should be present at 3500 RPM. If no vacuum, check for vacuum at carburetor side of delay valve. If vacuum, replace valve. If no vacuum is present, inspect check valve and carburetor port.
  2. Reconnect advance hose, then remove delay valve. Connect a hand vacuum pump and 11 in. (280 mm) piece of 1/8 in. (3.5 mm) I.D. hose to check valve side of delay valve. Plug ports on delay valve that are connected to air cleaner bleed and distributor.
  3. Apply vacuum and check for leaks. If leaks are found, replace valve. Apply vacuum to distributor port of valve and check for restriction. If vacuum can be held, replace valve.
  4. Plug port on valve that goes to air cleaner bleed. Apply 15 in. (380 mm) Hg vacuum to check valve side and watch for vacuum bleed. Vacuum should decrease to 5 in. (130 mm) Hg in 4-9 seconds. If not, replace valve.
    NOTE: If specified hose length and diameter are not used, vacuum leak times may vary.
  5. Connect vacuum pump to distributor diaphragm. Reconnect all other hoses and start engine. Pull 13 in. (330 mm) Hg vacuum; timing should advance and hold. If not, replace advance unit diaphragm.
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