Econoline E350 1 Ton V8-5.4L CNG VIN M (1999)
Variable Induction System: Description and Operation
The variable resonance induction system is used only on this engines. A solenoid-operated shutter valve is located in the dynamic chamber of the
variable resonance induction system in the lower intake manifold. The variable resonance induction system opens and closes the shutter according to the
engine speed and throttle opening angle to improve the charging efficiency by using the pressure waves of the intake air. The Powertrain Control Module
(PCM) applies voltage to the variable resonance induction system solenoid, and actuates and moves the shutter valve.