Caprice Wagon V8-305 5.0L (1986)
Canister Purge Control Valve: Technical Service Bulletins
EVAP Canister Control Valve - Diagnostic Procedure
Number:
86-254-6E
Section:
6E
Date:
OCT., 1987
Subject:
CANISTER CONTROL VALVE DIAGNOSIS ON VEHICLES
Model and Year: 1982-86 CAPRICE, CAMARO, MONTE CARLO, EL CAMINO MODELS EQUIPPED WITH 3.8L V6, 4.4L, 5.0L AND 5.7L V-8
CARBURETED ENGINES
TO:
ALL CHEVROLET DEALERS
FIG 1
Some four port canister control valves have been replaced as a result of fuel found in the valve or in the carb bowl vent line (refer Figure 1). The
presence of fuel found in this area does not necessarily indicate a faulty valve. The function of the valve can easily be checked on the vehicle by
following the service procedure outlined below:
FIG 2
On Vehicle Diagnosis
1.
Remove the hose connected to the control vacuum port (small top port) on the canister control valves.
2.
Connect a hand vacuum pump to the port (refer Figure 2) and apply 15" Hg. vacuum. If the diaphragm holds vacuum for at least 20 seconds,
reconnect the hose and proceed to step 3. If the valve fails to hold vacuum replace the valve.
3.
Start the engine and warm it up to normal operating temperature.