My 1988 G20 air managment valve spills air continously into the air cleaner . I understand it should be routing it to the exhaust manifolds most of the time. My question is is this valve either an open or closed valve, or is it contimously adjusting the air the air flow?
I think the OP is referring to the emissions air injection (or smog pump) system.
From the manual:
When the engine is cold or in wide open throttle condition, the ECM energizes the solenoid on the valve and air is directed to the exhaust manifold ports. When the coolant temperature increases, the solenoid is de-energized and air goes into the air cleaner which also acts as a silencer. At higher engine speeds, air is directed to the air cleaner through the pressure relief valve even though the solenoid may be energized.
There should be no air going to the exhaust ports while operating in the "Closed Loop” mode.
During engine decel, when there is a rise in the manifold vacuum signal, air is directed to the air
What the OP is describing appears to be normal (note bold emphasis above, added by me). This can be checked by removing the air hose from the air cleaner and noting the air flow when the engine is started (at full operating temp). Air should flow to the exhaust ports for about five seconds, then flow should switch to the air cleaner.
The manual I have is unclear!