California Models
- With engine at normal operating temperature and idling, place finger over relief air opening in air cleaner and check for presence of air.
- Disconnect vacuum hose from Combined Air Control (CAC) valve and plug hose to prevent engine from stalling. Air should now be discharged from CAC valve if valve is functioning properly.
- Next, connect a hand-held vacuum pump to CAC valve. See Fig 1. Apply 7.9-9.8 in. Hg to valve, then increase engine speed to 3000 RPM. Make sure no air leaks from CAC valve.
- With vacuum applied and engine at 3000 RPM, disconnect and plug air hose at check valve. Air should now leak from CAC valve. If not, replace CAC valve.