Ford F150 Pickup. Instruction - part 1618

and the other is opened and closed with a butterfly valve plate(s). IMRC housing uses a return spring to hold 
butterfly valve plate(s) in closed position. Electric actuator houses an internal switch or switches, dependent on 
application, to provide feedback to PCM indicating butterfly valve plate(s) position. 

When engine speed is less than 3000 RPM, electric actuator will not be energized, allowing IMRC butterfly 
valve plate(s) to remain in closed position. When engine speed is approximately 3000 RPM or more, electric 
actuator is energized, causing butterfly valve plate(s) to the open position to improve high speed engine 
performance. Some applications will activate IMRC butterfly valve plate(s) when engine speed is about 1500 
RPM. 

Fig. 3: View Of Intake Manifold Runner Control System (Electrically Actuated) 
Courtesy of FORD MOTOR CO. 

 

2003 Ford Pickup F150 

2003 ENGINE PERFORMANCE Theory & Operation - CNG, Flex-Fuel & Gasoline

  

Fig. 4: Identifying Intake Manifold Runner Control System - Econoline & Pickup 4.2L (VIN 2) 
Courtesy of FORD MOTOR CO. 

 

2003 Ford Pickup F150 

2003 ENGINE PERFORMANCE Theory & Operation - CNG, Flex-Fuel & Gasoline

  

Fig. 5: Identifying Intake Manifold Runner Control System - Focus 2.0L (VIN P) 
Courtesy of FORD MOTOR CO. 

 

2003 Ford Pickup F150 

2003 ENGINE PERFORMANCE Theory & Operation - CNG, Flex-Fuel & Gasoline

  

Fig. 6: Identifying Intake Manifold Runner Control System - Windstar 3.8L (VIN 4) 
Courtesy of FORD MOTOR CO. 

Intake Manifold Swirl Control Vacuum Actuated System - Ranger 2.3L (VIN D) 

Intake Manifold Swirl Control (IMSC) vacuum actuated system consists of manifold mounted vacuum actuator 
and Powertrain Control Module (PCM) controlled electric solenoid. See Fig. 7 and Fig. 8 . PCM monitors 
Throttle Position (TP) sensor, cylinder head temperature sensor and crankshaft position sensor signals to 
determine activation of IMSC. A positive change in voltage from TP sensor along with increase in RPM at 
proper engine temperature must be present to open valve plates. When conditions are met to open valves, PCM 
energizes IMSC solenoid and vacuum is then applied to actuator to pull butterfly plates open. 

Linkage from actuator attaches to manifold butterfly plate lever. IMSC actuator and manifold are a 
composite/plastic with a single intake air passage for each cylinder. The passage has a butterfly valve plate that 
blocks 60 percent of intake opening when actuated, leaving top of intake passage open to generate turbulence. A 
return spring is used to hold butterfly valve plates closed. Vacuum actuator provides feedback to PCM 
indicating butterfly valve plate position. 

When engine speed is less than 3000 RPM, vacuum solenoid will be energized to allow manifold vacuum to be 
applied and butterfly valve plates will remain closed. When engine speed is 3000 RPM or more, vacuum 

 

2003 Ford Pickup F150 

2003 ENGINE PERFORMANCE Theory & Operation - CNG, Flex-Fuel & Gasoline