K 30 P/U 4WD V6-262 4.3L (1985)
top of valve.
18.
Remove plugs covering idle mixture needles as outlined under ``Concealment Plug Removal'' in the appropriate carburetor section.
19.
Turn each mixture needle clockwise until lightly seated, then back screws out approximately three turns.
20.
Reinstall carburetor using new gasket, then disconnect and plug vacuum hose to canister purge valve.
21.
Start engine and allow to reach normal operating temperature, then place transmission in Drive (manual transmission in Neutral).
22.
Turn each mixture needle equally in 1/8 turn increments until dwell varies between 25°-35°, as close to 30° as possible. If reading is too low, turn
mixture needles counterclockwise. If too high, turn needles clockwise. Allow dwell readings to stabilize after each adjustment.
23.
Stop engine. Seal mixture needle cavities with RTV sealant or equivalent.
24.
Check and, if necessary, adjust fast idle speed to specification.
25.
Install air cleaner, then reconnect vacuum hoses.
