Chrysler Caravan/Voyager/Town n Country 1984-1995

Air Injection System

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See Figure 1



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Fig. Fig. 1: Air injection system-2.2L engines (Federal/Canadian model shown)

2.2L engines are equipped with an air injection system. This system is designed to supply a controlled amount of air to the exhaust gases, through exhaust ports, aiding in the oxidation of the gases and reduction of carbon monoxide and hydrocarbons to an appreciable level.

During engine warm-up air is injected into the base of the exhaust manifold. After the engine warms up, the air flow is switched (by a Coolant Vacuum Switch Cold Open or by a vacuum solenoid) to the 3-way catalytic converter where it further aids in the reduction of carbon monoxide and hydrocarbons in the exhaust system.

The system consists of a belt driven air pump, hoses, a switch/relief valve and a check valve to prevent the components within the system separate from high temperature exhaust gases.

No repairs are possible on any of the air injection system components. All replacement parts must be serviced as a unit.

REMOVAL & INSTALLATION



Coolant Vacuum Switch Cold Open
  1. Locate the switch on the thermostat housing.
  2.  
  3. Label the hoses before removing. Remove hoses.
  4.  
  5. Remove the vacuum switch from housing.
  6.  

To install:
  1. Install a new vacuum switch and connect the vacuum hoses. (See under hood vacuum hose routing label).
  2.  

Air Pump

See Figures 2, 3 and 4



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Fig. Fig. 2: Loosening the air pump mounting and pivot bolts



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Fig. Fig. 3: Removing a mounting bolt from the air pump



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Fig. Fig. 4: Removing the air pump and belt from the engine-1987 2.2L engine shown

The air injection system is not completely noiseless. Do not assume the air pump is defective because it squeals. If the system creates excessive noise, remove the drive belt and operate the engine. If the noise ceases, check all hose connections for proper tightening. Replace pump, if necessary.

  1. Remove all hoses and vacuum lines from the air pump and diverter valve or switch/relief valve (depending on how equipped).
  2.  
  3. Remove the air pump drive pulley shield.
  4.  
  5. Remove the air pump pivot bolt and remove air pump belt.
  6.  
  7. Remove the remaining mounting bolts and remove pump.
  8.  
  9. Remove the diverter valve or switch/relief valve from pump.
  10.  

To install:
  1. Clean all gasket material from valve and pump mounting surface.
  2.  
  3. Install the diverter valve or switch/relief valve using a new gasket, to the new pump.
  4.  
  5. Install the pump on the engine and loosely install pivot bolt.
  6.  
  7. Install the drive belt and tighten pivot bolt.
  8.  
  9. Install the air pump drive pulley shield.
  10.  
  11. Install all hoses and vacuum lines.
  12.  

Switch/Relief Valve

If vacuum is applied to the valve and air injection is not upstream, or if air injection is in both upstream and downstream, the valve is faulty and must be replaced.

  1. Remove all air hoses and vacuum hoses.
  2.  
  3. Remove the valve-to-pump mounting bolts, and remove valve.
  4.  

To install:
  1. Clean all gasket material from mounting surfaces.
  2.  
  3. Install the new valve to the pump with a new gasket.
  4.  
  5. Secure the valve with mounting bolts, tighten bolts to 125 inch lbs. (14 Nm).
  6.  
  7. Reinstall all air hoses and vacuum hoses.
  8.  

Relief Valve

The purpose of this valve is to control air pump pressure during high engine speeds. If the pump discharge pressure exceeds 9 psi (62 kPa) the valve will open and vent the excess pressure to the atmosphere.

  1. Remove the air hoses from the valve.
  2.  
  3. Remove the valve mounting screws and remove valve.
  4.  

To install:
  1. Clean all gasket material from mounting surfaces.
  2.  
  3. Install a new gasket on valve and secure with mounting screws.
  4.  
  5. Reconnect the air hoses.
  6.  

Check Valve

The check valve is located in the injection tube which leads to the exhaust manifold and converter assembly. The valve has a one-way diaphragm to protect the pump and hoses from high exhaust system pressure if the belt or pump fails.

Remove the air hose from check valve inlet tube. If exhaust gas escapes from the inlet tube, the valve have failed and must be replaced.

  1. Loosen clamp and remove inlet hose from the valve.
  2.  
  3. Remove the tube nut retaining the tube to the exhaust manifold or catalyst.
  4.  
  5. Loosen the starter motor mounting bolt and remove injection tube from engine.
  6.  
  7. Remove the catalytic converter injection tube mounting screws from catalytic converter flange and remove injection tube.
  8.  

To install:
  1. Position the injection tube to catalytic converter flange and secured with mounting screws.
  2.  
  3. Install the injection tube into fitting in exhaust manifold and bracket at starter motor.
  4.  
  5. Connect hoses to the check valve.
  6.  

 
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