G 10 1/2 Ton Van V8-305 5.0L VIN H 4-bbl (1984)
MIXTURE ADJUSTMENT
1.
Remove plugs covering idle mixture adjusting screws as outlined under ``Concealment Plug Removal'' in the appropriate carburetor section.
2.
Turn each mixture adjusting screw in (clockwise) until lightly seated, then back screws out 3 turns.
3.
Reinstall carburetor, leaving air cleaner off and applicable vacuum fittings plugged.
4.
Connect dwell meter to MC solenoid test lead and set meter on 6 cylinder scale.
5.
Disconnect and plug hose to canister purge valve, start engine and run until it reaches normal operating temperature.
6.
Place transmission in drive (neutral for manual transmission) and ensure that curb idle speed is within specifications.
7.
Adjust idle mixture screws equally, turning each screw 1/8 of a turn at a time, until dwell reading fluctuates in the 25-35° range, as close to 30° as
possible. Allow time between each adjustment for dwell readings to stabilize. If readings are less than 25°, rotate screws counterclockwise; if
readings are above 35°, rotate screws clockwise.
8.
When specified dwell reading has been obtained, ensure that curb idle speed is within specifications, then seal mixture adjusting screw cavities
with RTV sealer. If specified dwell readings cannot be obtained after completing calibration procedure, disassemble and repair carburetor as
needed.
