Should the engine stall out when the idle adjustment screw is completely closed?
 

I'm still dealing with a rough idle and I've now moved on to inspecting the air valve operation by fully screwing in the idle speed adjustment screw.

The FSM says that when the engine is cold (below 176 F) and the idle adjustment screw is fully screwed into the TB, the engine rpm should drop. It did not say that the engine should stall out.

The FSM also says that when the engine is warm and the idle adjusting screw is fully in, the engine rpm should drop below the idle speed stop (I don't understand this statement). It did not say however, that the engine should stall out.

I've noticed that irregardless of whether the engine is either cold or warm, and the idle adjustment screw is fully in, the engine stalls out. I've cleaned the TB, the screw, and correctly adjusted the TPS. I've got no codes.

I have a TB with a coolant hose that feeds in from one side of the TB and then another that comes out the other side. I've read from another post that the changing temperature of the coolant varies the size of an orifice inside the TB which in turn affects the air valve operation.

Any suggestions would be appreciated.

Troy

bump...

mine stalls if i turn it all the way in, but only if i do it fast, if i turn it in very slowly i can get it to idle with the screw all the way in but the idle is about 300-400 rpm

Mine will stall out regardless of how fast or slow I turn it in. I'm wondering if this is a clue to my rough idle.

Anyone else out there try this test? Apparently, it's a test for the air valve.

Troy