Component Tests and General Diagnostics

CANNISTER CONTROL VALVE


Apply a short length of hose to the carburetor bowl tube of the canister control valve and blow into it. Air should pass out through the canister tube and the purge valve tube. If it does not, valve must be replaced. Apply vacuum (15" or 51 kPa) to the manifold vacuum tube. It should hold vacuum for at least 20 seconds. If it does not, replace the valve. With vacuum still applied, again try to blow through the hose into the carburetor bowl tube. No air should flow from the canister tube or the purge vacuum tube. If it does, the diaphragm assembly is not sealing and the valve must be replaced.


THERMAL BOWL VENT VALVE (TBVV)

The TBVV may be tested by attaching a short piece of hose to the carburetor side of the valve and blowing through it. When the TBVV is below 32~C (90~F) no air should pass through it. When the TBVV is above 49~C (120~F) air should pass through it.