Suburban 3/4 Ton 4WD V8-305 5.0L (1986)
Canister Purge Control Valve: Testing and Inspection
EXCEPT 1987 V6-262, V8305, 350 & 454 HIGH ALT. ENGINES
1.
Disconnect purge valve vacuum line and check for vacuum with engine operating above 1500 RPM. If no vacuum is present, perform EGR check.
2.
Using hand-held vacuum pump, apply vacuum to purge valve control diaphragm and note vacuum reading. Valve should hold vacuum. If purge
valve loses vacuum, replace vacuum canister.
3.
If purge valve holds vacuum, disconnect purge line and check for presence of vacuum with engine running. If no vacuum is present, check PCV
hoses and system. Repair or replace as necessary.
