Prelude Models Only
- Disconnect hose No. 30 from frequency solenoid valve B and connect vacuum gauge to hose. See Figure . Start engine and allow to run at idle speed.
- Vacuum reading after engine stabilizes, should be 4-8 in. Hg vacuum. If vacuum is within range, constant vacuum valve is okay. Reconnect hose to frequency valve B. If vacuum stabilizes above or below specified range, replace constant vacuum valve.