I am have a misfire issue with my 2000 Ranger 2.5 liter manual transmission. I was looking in the engine compartment for a vacuum leak and found a broken off grey plastic tube.....I can't find where this tube broke off from. It is about 3/16" in diameter, made of hard grey plastic. It runs in some "hooks" which are part of the "evaporator case" at the passenger side rear of the engine compartment. See picture attached.
Can someone tell me what this grey tube is and where it goes? Thanks.

 

Not a vacuum leak
Grey line runs from the Heater Hose By-pass valve to inside the cab, to the Climate control panel
If you look down between heater fan box and inner fender there are TWO lines that come out of the firewall
A Black line that runs to the vacuum reservoir "ball" lower passenger side front
A grey line that runs to heater by-pass valve

The Black line provides vacuum to control the Vents in the cab, air flow direction, defrost, panel, floor are the vent selections
Defrost is the default or "no vacuum" setting, so if your vents don't work then this black line is broken

When you select AC MAX the climate control sends vacuum on the grey line to the heater by-pass, closing off flow thru heater core in the cab to help with "MAX" cooling
So this would not be a vacuum leak that could effect engine, as vacuum comes from the Reservoir, not directly from the engine

Picture of inside the cab passenger firewall: https://www.explorerforum.com/forums...pi-jpg.198133/
Inertia switch is what arrow points to, look just above it and you will see the TWO vacuum line connections
Black goes to black in engine bay
White changes to Grey in engine bay

 

Many Thanks. I could not seem to find a diagram that showed that grey tube.
You saved me a bunch of time looking for it!
Thanks again. Paul G