There is this thing called tandem valve on 90 STD, DPFI engine. The valve is in the positing of a choke valve would be if it was a carburetor equipped engine. I was looking into the throat and it is in closed position. Engine is not running and is cold.

Got curious and pushed to see if it opens all the way.

It seems like dash-pot is limiting how far the valve opens and is not opening as a choke valve would open. There is solenoid in the system to control something here, may be vacuum.

How far does this tandem valve opens? The engine runs fine and there is no issue with temp or operation, so it must be working fine. I am just kind of curious about this tandem valve thing here.