B250 3/4 Ton Van V8-360 5.9L VIN T 4-bbl (1982)
Air Injection Control Valve: Testing and Inspection
Switch/Relief Valve
Failure of the switch/relief valve is indicated when vacuum is applied to the valve and air injection is not directed upstream (to the exhaust
manifold crossover tube), or if air is injected both upstream and downstream. If the relief valve fails, air will escape from the silencer at engine idle
speed. This valve is not serviceable and must be replaced if defective.
