Idle Needle Adjustment Procedure B

1. IDLE MIXTURE ADJUSTMENT B on the vehicle to obtain correct dwell readings.


A. Remove idle mixture needle plugs, following instructions under CONCEALMENT PLUG REMOVAL

B. Using Tool JD-29030-B, BT-7610-B, or equivalent, turn each idle mixture needle clockwise until lightly seated, then turn each mixture needle counterclockwise 3 turns.

C. Reinstall carburetor on engine, using a new flange mounting gasket, but do not install air cleaner or gasket at this time.

D. Start engine and allow it to reach normal operating temperature (drive wheels blocked).

E. While idling in Drive (Neutral for manual transmission), adjust both mixture needles equally, in 1/8 turn increments, until dwell reading varies within the 25-30~ range, attempting to be as close to 30~ as possible. If reading is too low, turn mixture needies counterclockwise. If reading is too high, turn mixture needles clockwise. Allow time for dwell reading to stabilize after each adjustment. After adjustments are complete, seal the idle mixture needle openings in the throttle body, using silicone sealant, RTV rubber, or equivalent. The sealer is required to discourage unnecessary readjustment of the setting, and to prevent fuel vapor loss in that area. On vehicles WITHOUT a carburetor-mounted Idle Speed Control motor adjust curb idle speed if necessary.