Marquis L4-140 2.3L VIN A 1-bbl (1986)
Air Injection Check Valve: Testing and Inspection
Air Check Valve/Pulse Air Valve
1. Inspect all hoses, tubes and the air valve for leaks.
2. Disconnect the hose on the inlet side of the air valve, and connect the check valve tester T75L-9487-A or equivalent as shown in Fig. 2. Note that a 6
inch length of tube, securely clamped, should be used between the valve and the tester.
3. Squeeze the rubber bulb on the tester as flat as possible, then release it. The bulb should remain creased for 8 seconds and should not return to a
normal shape until after 15 seconds.
If the above tester is not available, blow through the check valve, toward manifold, then attempt to suck back through the valve; the valve should free
flow in the direction of the exhaust manifold only.
4. For the pulse air valve only: after starting the engine and at curb idle, a suction should be felt at the valve inlet. If not, replace the valve.
