first you have to turn the valve and see if it was just in a wrong position
There is a proportioning valve and once the repair is done and you have bled all the air out of the system the valve should reset itself unless it is stuck. If it is stuck you may have to replace the valve assembly if you can't free it up.
sounds like the carb needle valve is stuck or something is stuck in it. not a do it yourself repair, might need new carb. good luck
It is just stuck,
The valve has failed.The valve has failed.
stuck valve in valve body? solenoid valve faulty if it has one?
When you shake the PCV valve it should rattle. If it does not rattle then it is probably stuck and should be replaced.
Always take it to a repair shop if you're having a lot of trouble. You don't want to damage the instrument further. However, sticky valves are quite common. If the valve is stuck up, push it down. Remove the bottom screw and gently push the valve out the top of the horn (with your finger or if that doesn't work, a drum stick). Then use "valve oil" (not slide oil) and apply liberally all over the valve. Replace the parts and you should be good to go! If this isn't working you need to take it into a repair shop.
is it a powershift or direct drive if powershift overhaul control valve probably an o ring or a seal or a broken spring is it a powershift or direct drive if powershift overhaul control valve probably an o ring or a seal or a broken spring
buy a new valve
As a 33+ year HVAC veteran, it's been my experience that, even if you can "free up" a stuck zone valve, it will stick again. If it's actually the valve itself that's stuck, rather than the "actuator" motor having failed, then it's usually best to replace the valve body.
Sure if the valve gets stuck open and the flapper get stuck closed.