Toyota Pick-ups/Land Cruiser/4Runner 1989-1996

Evaporative Emission Controls

Print

OPERATION



The evaporative emission control system prevents the release of unburned hydrocarbons from the liquid gasoline vapor into the atmosphere. Evaporative fuel vapor from the tank is routed to the charcoal canister located in the engine compartment. The charcoal canister stores the vapor until the engine coolant temperature reaches 129°F (54°C). When the engine coolant temperature is above 129°F (54°C) and the throttle is open, a vacuum switching valve opens to allow vapors trapped in the canister to enter the intake manifold.

A fuel filler cap with a check valve allows air to enter the fuel tank as the fuel is used. This prevents a vacuum build-up in the fuel tank as the engine is running.

COMPONENT TESTING



Charcoal Canister

EXCLUDING 3RZ-FE



See Figures 1 and 2

  1. Label and disconnect the vacuum hose at the top of the canister. Remove the charcoal canister from the vehicle.
  2.  



Click image to see an enlarged view

Fig. Fig. 1: Always label hoses and wires prior to removal

  1. Remove the vacuum switching valve.
  2.  



Click image to see an enlarged view

Fig. Fig. 2: The hoses are easily removed by sliding the clamp off the port end

  1. Look for cracks or damage to the outside of the canister.
  2.  
  3. Using a low pressure of compressed air 0.68 psi (5 kPa), blow into the tank pipe and check that air flows without any resistance from the other pipes.
  4.  
  5. Blow air into the purge pipe and check that air does not flow from the tank pipe and air flows without resistance from the other pipe. If there is any problems found, replace the canister.
  6.  
  7. Clean the filter in the canister by blowing 43 psi (296 kPa) of compressed air into the canister tank pipe while holding the other upper canister tank pipe closed.
  8.  

Do not attempt to wash the canister. No activated carbon should come out of the canister while cleaning or inspecting the unit. If it does, replace the canister.

  1. Install the canister on the vehicle and reconnect the hoses.
  2.  

3RZ-FE ENGINE

See Figures 3, 4, 5 and 6

  1. Label and disconnect the vacuum hose at the top of the canister. Remove the charcoal canister from the vehicle.
  2.  
  3. Remove the vacuum switching valve.
  4.  
  5. Look for cracks or damage to the outside of the canister.
  6.  
  7. Install the plugs to ports A and B .
  8.  



Click image to see an enlarged view

Fig. Fig. 3: Location of the ports and plugs

  1. While holding port C closed, blow air 0.21 psi (2 kPa) into port D and check that air does not flow from port F .
  2.  



Click image to see an enlarged view

Fig. Fig. 4: Blow air into port D and check that air does not flow from port F

  1. Apply vacuum 0.87 in. Hg (3 kPa) to port C , check that the vacuum does not decrease when port F is released.
  2.  



Click image to see an enlarged view

Fig. Fig. 5: Apply vacuum to port C

  1. While holding port F closed, apply 0.87 in. Hg (2.94 kPa) of vacuum to port D . Check that the vacuum does not decrease when port C is closed, and check that the vacuum decreases when port C is released. If a problem occurs, replace the charcoal canister.
  2.  



Click image to see an enlarged view

Fig. Fig. 6: Your finger can be used to plug port C

  1. Remove the plugs.
  2.  
  3. Reinstall the canister.
  4.  

Thermal Vacuum Valve (TVV)1FZ-FE ENGINE See Figures 7 and 8

  1. Disconnect the negative battery cable.
  2.  
  3. Drain the engine coolant from the radiator.
  4.  



Click image to see an enlarged view

Fig. Fig. 7: The TVV is located near the oil filter as shown here

  1. Remove the TVV from the engine cylinder head.
  2.  
  3. Check that air blown into pipe J exits out the air filter on the top of the valve. This is a closed valve reaction.
  4.  
  5. Heat the TVV in water to a temperature above 147°F (64°C).
  6.  



Click image to see an enlarged view

Fig. Fig. 8: Heat the valve in hot water

  1. Check that air blown into pipe J exits out pipe K of the valve.
  2.  
  3. If the TVV operation differs from specifications, replace the valve.
  4.  

3VZ-E ENGINE
  1. Disconnect the negative battery cable.
  2.  
  3. Drain the engine coolant from the radiator.
  4.  
  5. Remove the TVV from the engine intake manifold.
  6.  
  7. Blow air into the pipe and check that the valve is closed.
  8.  
  9. Heat the TVV in water to above 129°F (54°C).
  10.  
  11. Blow air into the pipe and check that the TVV is open.
  12.  
  13. If the TVV operation differs from specifications, replace the valve.
  14.  

Vacuum Switching Valve (VSV)22R ENGINE See Figure 9

  1. Disconnect the VSV electrical wiring.
  2.  
  3. Connect the VSV terminals to the battery terminals using jumper wires.
  4.  



Click image to see an enlarged view

Fig. Fig. 9: The 22R VCV should only open when power is applied

  1. Blow into the pipe and check that the valve is open.
  2.  
  3. Disconnect the positive battery terminal jumper wire.
  4.  
  5. Blow into the valve and check that the valve is closed.
  6.  
  7. If the valve is not operating properly, replace it.
  8.  

T100 WITH 3VZ-E ENGINE
  1. Disconnect the negative battery cable. Remove the VSV from the engine.
  2.  
  3. Connect the VSV terminals to the battery using jumper wires.
  4.  
  5. Blow air into pipe E and check that air comes out of pipe F . Disconnect the battery from the VSV.
  6.  
  7. Blow air into pipe E and check that air does not come out of pipe F . If a problem exists, replace the VSV.
  8.  
  9. Check the VSV for short circuit using an ohmmeter. Check that there is no continuity between the terminals and the body of the VSV. If continuity exists, replace the VSV.
  10.  
  11. Check the VSV for an open circuit. Using an ohmmeter, measure the resistance between the terminals. Compare the measured resistance to the desired range of 30-50 ohms at 68°F (20°C). If the resistance is not within specification, replace the VSV.
  12.  

2RZ-FE AND 3RZ-FE ENGINES
  1. Remove the VSV, by disconnecting the harness and the EVAP hoses from the unit.
  2.  
  3. On the 3RZ-FE, remove the 2 bolts and screw from the unit.
  4.  
  5. Inspect the VSV for an open circuit as follows:
    1. Using an ohmmeter, check that there is continuity between the terminals. The resistance should be 30-34 ohms at 68°F (20°C).
    2.  

  6.  
  7. Check for ground as follows:
    1. Using an ohmmeter, check that there is no continuity between each terminal and the body. If there is continuity, replace the VSV.
    2.  

  8.  
  9. Check the operation of the VSV as follows:
    1. Ensure that air does not flow from ports E to F . Never apply more than 13.5 psi (93 kPa) of compressed air to the VSV valve.
    2.  
    3. Connect the battery to the terminals using jumper wires. Check that the air flows from ports E to F . If not, replace the VSV.
    4.  

  10.  
  11. Reinstall the VSV.
  12.  

1FZ-FE ENGINE
  1. Disconnect the negative battery cable. Remove the VSV from the engine.
  2.  
  3. Inspect the VSV for an open circuit using an ohmmeter. Check that there is continuity between terminals on the VSV. Compare measured resistance to desired range of 30-33 ohms at 68°F (20°C). If no continuity or the measured resistance differs from specifications, replace the VSV.
  4.  
  5. Inspect the VSV for ground. Using an ohmmeter, check that there is no continuity between each terminal and the VSV body. If continuity is present, replace the VSV.
  6.  
  7. Inspect VSV operation:
    1. Check that air does not flow from pipe E to pipe F .
    2.  
    3. Connect the battery to the terminals using jumper wires.
    4.  
    5. With battery voltage applied, check that air does pass from pipe E to pipe F .
    6.  

  8.  
  9. If test results differ from specifications, replace the VSV.
  10.  

Vacuum Control Valve (VCV)

See Figures 10 and 11

  1. Remove the VCV from the engine.
  2.  
  3. Apply more then 2.8 in. Hg (9.3 kPa) of vacuum to pipe S of the VCV.
  4.  
  5. Blow air into pipe Y and check that air comes out of pipe Z .
  6.  



Click image to see an enlarged view

Fig. Fig. 10: When you blow air into port Y with vacuum applied, air should flow

  1. Disconnect the vacuum source.
  2.  
  3. Blow air into pipe Y and check that air does not come out of pipe Z .
  4.  



Click image to see an enlarged view

Fig. Fig. 11: Air should not flow when you blow air into port Y with vacuum disconnected

  1. If test results differ from specifications, replace the VCV.
  2.  

Outer Vent Control Valve

See Figures 12, 13 and 14

This applies only to the 22R engine.

  1. Disconnect the outer vent hose from the carburetor.
  2.  
  3. Blow air into the outer vent pipe and check that the vent control valve is open.
  4.  



Click image to see an enlarged view

Fig. Fig. 12: While the engine is not running, blow air into the outer vent pipe to ensure the valve is open

  1. Start the engine.
  2.  
  3. While idling, blow air into the outer vent pipe and check that the outer vent control valve is closed.
  4.  



Click image to see an enlarged view

Fig. Fig. 13: While the engine is running, blow air into the outer vent pipe to ensure the valve is closed

  1. Unplug the solenoid wiring connector.
  2.  
  3. Using an ohmmeter, measure the resistance between the positive (+) terminal and the solenoid body. Resistance should be 63-73 ohms at 68°F (20°C).
  4.  



Click image to see an enlarged view

Fig. Fig. 14: Check the resistance with an ohmmeter

REMOVAL & INSTALLATION



Thermal Vacuum Valve (TVV)

See Figure 15

  1. Disconnect the negative battery cable.
  2.  
  3. Drain the engine coolant to a level below the valve.
  4.  
  5. Label and disconnect the vacuum hoses from the TVV.
  6.  
  7. Remove the TVV from the engine.
  8.  

To install:
  1. Apply sealant to the lower 2 or 3 threads of the TVV.
  2.  



Click image to see an enlarged view

Fig. Fig. 15: Apply adhesive sealant to the threads before installing it

  1. Thread the TVV into the engine. If equipped with 3VZ-E engine, tighten the TVV to 18 ft. lbs. (25 Nm). On 1FZ-FE engine, tighten TVV to 22 ft. lbs. (29 Nm).
  2.  
  3. Reconnect the vacuum hoses at their original locations an the cooling system.
  4.  
  5. Connect the negative battery cable.
  6.  

Vacuum Switching Valve (VSV)EXCLUDING 1FZ-FE

  1. Disconnect the negative battery cable. Drain the engine coolant.
  2.  
  3. Label and remove the vacuum lines.
  4.  
  5. Using an appropriate sized wrench, remove the valve.
  6.  

To install:
  1. Check the vacuum hoses for deterioration or damage. Replace as necessary.
  2.  
  3. Coat the lower threads of the valve with sealant, and install the valve.
  4.  
  5. Install the vacuum hoses in their original locations.
  6.  
  7. Fill the cooling system and check for leaks.
  8.  
  9. Connect the negative battery cable.
  10.  

1FZ-FE ENGINE
  1. Disconnect the negative battery cable.
  2.  
  3. Drain the engine coolant. Disconnect the cruise control cable, accelerator cable and the throttle cable at the throttle body.
  4.  
  5. Disconnect the vacuum hoses and the EGR gas temperature sensor connector at the EGR valve. Loosen the EGR pipe union nut. Remove the 2 nuts holding the EGR valve and air intake chamber. Remove the 2 stud bolts, EGR valve and vacuum modulator assembly.
  6.  
  7. Remove the bolt holding the heater pipe and the air intake chamber. Disconnect the air cleaner hose, if still attached.
  8.  
  9. Label and disconnect the PCV hoses. Label and disconnect the remaining vacuum hoses. Disconnect the brake booster hose.
  10.  
  11. Disconnect the water bypass hose and the EVAP hose. Disconnect the connector from the emission control valve set assembly, throttle position sensor and the Idle Air Control (IAC) valve.
  12.  
  13. Remove the power steering reservoir tank mounting bolts and position tank aside. Disconnecting the fluid lines should not be necessary.
  14.  
  15. Remove the engine oil dipstick and guide. Remove the O-ring from the end of the dipstick guide.
  16.  
  17. Disconnect the engine ground strap. Label and disconnect the vacuum lines from the TVV.
  18.  
  19. Remove the 4 bolts, 4 nuts, air intake chamber and 2 gaskets.
  20.  
  21. Disconnect the air hose and vacuum from the the air intake chamber.
  22.  
  23. Remove the 4 mounting bolt and the emission control valve set assembly.
  24.  
  25. Unplug the connector and the 2 vacuum hoses. Remove the screw and VSV.
  26.  

To install:
  1. Install the VSV with the mounting screws.
  2.  
  3. Connect the 2 vacuum hoses and the harness connector to the VSV.
  4.  
  5. Install the emission control valve set with the 4 mounting bolts and tighten to 14 ft. lbs. (20 Nm).
  6.  
  7. Connect the air hoses and the vacuum hoses to the air intake chamber.
  8.  
  9. Clean the old gasket material from all mating surfaces. Install 2 new gaskets and the air intake chamber with the 4 mounting nuts and 4 bolts. Tighten fasteners to 14 ft. lbs. (21 Nm).
  10.  
  11. Connect the heater bypass hoses. Connect the 2 vacuum hoses to the TVV, then attach the engine ground strap.
  12.  
  13. Install new O-ring to the bottom of the oil dipstick guide and lubricate lightly with clean engine oil. Install the guide into the hole in the oil pan and tighten the retainer bolts to 14 ft. lbs. (20 Nm).
  14.  
  15. Install the power steering reservoir in position and secure in place. Tighten the mounting bolts to 13 ft. lbs. (18 Nm).
  16.  
  17. Connect the harness connectors to the emission control valve set assembly, throttle position sensor and IAC valve.
  18.  
  19. Engage the vacuum hoses and the water bypass hoses. Install the air cleaner hose.
  20.  
  21. Install the bolt holding the heater inlet and intake chamber, tightening to 14 ft. lbs. (20 Nm).
  22.  
  23. Install a new gasket, EGR valve and vacuum modulator assembly with the mounting bolts. Tighten bolts to 8 ft. lbs. (10 Nm). Install the 2 nuts holding the EGR valve and air intake chamber and tighten to 14 ft. lbs. (19 Nm).
  24.  
  25. Tighten the union nut of the EGR pipe to 47 ft. lbs. (64 Nm). Connect the EGR gas temperature sensor connector and 3 vacuum hoses to the EGR valve.
  26.  
  27. Connect the throttle cable, accelerator cable and cruise control actuator cable to the throttle body.
  28.  
  29. Fill the cooling system and inspect for leaks.
  30.  
  31. Connect the negative battery cable.
  32.  

Vacuum Control Valve (VCV)

  1. Disconnect the negative battery cable.
  2.  
  3. Label and disconnect the lines at the VCV. Inspect lines for deterioration and replace as required.
  4.  
  5. Remove the VCV from the engine.
  6.  
  7. Installation is the reverse of the removal procedure.
  8.  

 
label.common.footer.alt.autozoneLogo