Toyota Celica 1986-1993 Repair Guide

Evaporative Emission Controls

Print

OPERATION





Click image to see an enlarged view

Fig. Fig. 1 Fuel Evaporative Emission Control (evap) system2S-E engine shown



Click image to see an enlarged view

Fig. Fig. 2 Gas cap check valve and seal should be in good shapeCelica



Click image to see an enlarged view

Fig. Fig. 3 Checking for a clogged filter and stuck charcoal canister check valveCelica



Click image to see an enlarged view

Fig. Fig. 4 Cleaning charcoal canister filterCelica

To reduce the hydrocarbon emissions, evaporated fuel from the fuel tank is routed through the charcoal canister to the intake manifold for combustion in the cylinders.

SERVICING



Fuel Lines and Gas Cap

Visually inspect all the fuel and vapor lines and connections for cracks, wear and sharp bends. Replace all damaged lines and tighten all loose connection. Visually inspect the fuel tank for deformation, cracks and fuel leakage. Remove the gas cap and check the cap and gasket for cracks and damage. If the gasket is worn, replace it with new one. If the cap is damaged, it should be discarded and replaced.

Charcoal Canister
  1. Remove the charcoal canister (See ).
  2.  
  3. Visually check the canister case.
  4.  
  5. Check for a clogged filter and stuck check valve.
    1. Using low-pressure compressed air, blow into the tank pipe and check that the air flows without resistance from the other pipes.
    2.  
    3. Blow into the purge pipe and check that the air does not flow from the other pipes.
    4.  
    5. If a problem is found, replace the charcoal canister.
    6.  

  6.  
  7. Clean the filter in the canister by blowing 43 psi of compressed air into the tank pipe, while holding the other upper canister pipe closed.
  8.  
  9. Install the charcoal canister.
  10.  

REMOVAL & INSTALLATION



Remove the charcoal canister from the vehicle as described in . Remember that the charcoal canister should not be washed or cleaned and none of the activated carbon inside the unit should come out. If the canister is found to be full of raw fuel, replace it with a new one.

Bimetal Vacuum Switching Valve (BVSV)
TESTING

The BVSV can be checked by blowing air into it at different temperatures.


CAUTION
When draining the coolant, keep in mind that cats and dogs are attracted by the ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

  1. Drain the coolant from the radiator into a suitable drain container.
  2.  
  3. Unscrew and remove the BVSV.
  4.  
  5. Place the BVSV into a container filled with cool water (below 95 degrees F).
  6.  
  7. Blow air into the unit and make sure the valve is closed.
  8.  
  9. Remove the unit from the container and place into a container filled with hot water (129 degrees F).
  10.  
  11. Blow air into the unit and make sure that the valve is open.
  12.  
  13. If the valve does not operate as described, replace it.
  14.  
  15. Coat the threads of the BVSV with a suitable liquid thread sealant and install.
  16.  
  17. Fill the radiator with a good brand of ethylene glycol coolant to the proper level.
  18.  
  19. Start the engine and check for leaks.
  20.  



Click image to see an enlarged view

Fig. Fig. 5 Checking BVSV for proper operation when coolCelica



Click image to see an enlarged view

Fig. Fig. 6 Checking BVSV for proper operation when warmCelica

REMOVAL & INSTALLATION

CAUTION
When draining the coolant, keep in mind that cats and dogs are attracted by the ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

  1. Drain the coolant from the radiator into a suitable drain container.
  2.  
  3. Unscrew and remove the BVSV.
  4.  

To install:

  1. Reverse the removal procedures to install. Coat the threads of the BVSV with a suitable liquid thread sealant.
  2.  

 
label.common.footer.alt.autozoneLogo