G 2500 3/4 Ton Van V8-350 5.7L VIN L 4-bbl (1983)
4. With engine running (choke wide open and transmission in neutral) adjust idle speed screw to curb idle speed. See: Idle Speed/Adjustments/Idle
Speed
5. Adjust each idle mixture needle to obtain highest RPM.
6. Repeat steps 4 and 5 until "best" idle is obtained.
7. If necessary, reset curb idle speed. See: Idle Speed/Adjustments/Idle Speed/Federal
8. After adjustments are complete, seal the idle mixture needle setting using silicone sealant or equivalent.
9. Check and if necessary, adjust throttle lever actuator.See: Idle Speed/Adjustments/Idle Speed
10. Check and if necessary, adjust fast idle speed. See: Idle Speed/Adjustments/Fast Idle Speed
11. Turn off engine, remove gages, unplug and reconnect vacuum hoses. Install air cleaner.
12. Remove block from drive wheel.
CONCEALMENT PLUG REMOVAL
-
Remove carburetor from engine to gain access to the plugs covering the idle mixture needles.
-
Invert carburetor on a suitable holding fixture, manifold side up.
NOTE: Use care to avoid damaging linkage, tubes, and parts protruding from the air horn.
-
Make two parallel cuts in the throttle body on either side of the locator points beneath the idle mixture needle plug (manifold side) with a hack
saw. The cuts should not extend more than 1/8 inch beyond the locator points. The distance between the saw marks depends on the size of the
punch to be used.
-
Place a flat punch at a point near the ends of the saw marks in the throttle body. Holding the punch at a 45 degree angle, drive it into the throttle
body until the casing breaks away, exposing the steel plug.
-
Holding a center punch vertical, drive it into the steel plug.
-
Then holding the punch at a 45 degree angle, drive the plug out of the casting.
NOTE: Hardened plug may break rather than remain intact. It is not necessary to remove the plug completely, instead, remove loose pieces.
-
Repeat procedure for the remaining mixture needle and re-install carburetor.