Bonneville V6-231 3.8L (1984)
Bowl Vent Valve: Customer Interest
Engine - Poor Performance/Low Fuel Mileage/MIL ON
Number 84-6 (Gasoline)-51
Date
7/84
Subject:
TESTING PROCEDURE FOR REMOTE CANISTER CONTROL VALVE (TYPE 1)
Affected Models:
ALL 1982-1984 3.8L (VIN CODE A) AND 4.1L (VIN CODE 4) BUICK BUILT ENGINES
Should a vehicle be received with comments of low fuel mileage, poor performance "Check Engine" light on with Code 45, the canister purge valve
should be checked per the procedures provided in this bulletin.
When diagnosing a condition such as rough idle, rich acceleration, or lean idle duty cycles (indications of rich carburetion), the following procedure
should be followed for diagnosis of a canister control valve:
1.
Apply a short length of 3/8" (9.5 mm) I.D. hose to the carburetor bowl tube of the canister control valve (see illustration) and blow very lightly
into it. Air should pass out through the canister tube. If it does not, replace the canister control valve.
2.
Use a hand vacuum pump to apply vacuum (15" Hg or 51 kPa) to the manifold vacuum tube.. The diaphragm should hold vacuum for at least 20
seconds. If it does not, replace the canister control valve.
3.
With vacuum still applied to the manifold vacuum tube, again try blowing lightly through the hose into the carburetor bowl tube. No air should
flow from the canister tube or purge vacuum tube. If air does pass through either tube, the valve is not sealing properly, and the canister control
valve must be replaced.
