Air Control Valve B

Fig. 44 Applying Vacuum To Air Control Valve 'B':

1. Disconnect the #32 hose from the vacuum hose manifold and connect a vacuum pump/gauge to the hose, Fig. 44.
2. Disconnect the lower hose from air control valve B, and warm up the engine to normal operating temperature (cooling fan should cycle on and off at least once). With the engine at idle, there should be no vacuum.
3. With the engine at idle, apply vacuum to hose #32. The engine should stall, and the valve should hold vacuum.
4. If the valve fails either test, check the #32 vacuum hose for correct routing or leaks, and if the hose is OK, replace the air control valve and re-test.
5. Install a 'T' fitting and a vacuum pump between the #32 hose and the fitting on the air control valve. Vacuum should be:

At idle No vacuum
At 2500 rpm 70 - 170 mbar (2 - 5 in. Hg)

6. If the valve fails either test, check Frequency Solenoid Valve B.