Where is the PVC valve located on a 1986 5 liter Mustang GT with fuel injection?

On a 1986 Mustang GT 5.0L with fuel injection, the Positive Crankcase Ventilation (PCV) valve isn't a single, easily identifiable valve like in some systems. Instead, it's integrated into the intake manifold.

You won't find a separate PCV valve; look for a hose connected to the valve cover that leads directly into the intake manifold. The point where that hose connects to the manifold is functionally where the PCV valve is incorporated. It's not a replaceable part in the same way as a standalone PCV valve on other engines.