R 1500 P/U 2WD V6-262 4.3L (1987)
Canister Purge Control Valve: Testing and Inspection
1987 V6-262, 305, 350 & 454 HIGH ALTITUDE ENGINES
1.
Attach a short length of vacuum hose to canister purge valve lower tube and attempt blow through it. On canisters less constant purge hose, no air
should pass into canister. On canisters with constant purge control hole, a small amount air should pass into the canister.
2.
Using a suitable hand held vacuum pump, apply approximately 15 inches Hg. of vacuum to canister purge valve upper tube. Purge valve
diaphragm should hold vacuum for at least 20 seconds. If purge valve does not hold vacuum, the canister assembly should be replaced.
3.
With vacuum applied to canister purge valve upper tube, try again to blow through hose attached to lower tube. If an increase in air flow is not
noted, replace canister assembly.
