Poor Drivability - Check Throttle Synchronization (SECTION 19, NO. 36)

SETTING THROTTLE VALVES

1. Check that both throttle valves are centered horizontally and vertically in the throttle bodies.
2. With the throttle valve closed, use a feeler gauge to check the clearance between the throttle valve and the throttle body See Fig 1 . Throttle valve checking clearance: 0.001 - 0.003 inch (0.025 - 0.076 mm). Check the clearance at the bottom as well as at the top of the throttle valve. If a significant difference is found between the top and bottom measurements, the throttle valve may be offset on its shaft. If both measurements are within the above range, do NOT adjust the throttle stop screw See Fig 1 .
3. If adjustment is necessary, set the throttle stop screw to achieve the following throttle valve clearance range: Throttle valve setting clearance: 0.001 - 0.0015 inch (0.025 - 0.040 mm). After completing throttle valve adjustment, seal the locknuts with a dab of paint.
4. Repeat the checking procedure on the opposite throttle valve.

Fig 1: Checking Throttle Valve Clearance

SETTING THROTTLE LINKAGE

Use the following procedure to obtain the required backlash in the throttle linkage to ensure correct synchronization of throttle opening.

1. Loosen both locknuts on the two linkage rods between the center throttle turntable and the throttle levers.
2. Disconnect one linkage rod from its ball pin on the linkage rod bracket.
3. Position a 0.079 inch (2.00 mm) spacer between the linkage rod bracket and its stop See Fig 2 .
   Fig 2: Location Of Setting Spacer

   
4. Turn the linkage rod that is still connected to increase its length until the throttle lever clears its stop screw.
5. Shorten the linkage rod until the throttle lever just touches its stop screw. Tighten both lock nuts on the linkage rod.
6. connect the second linkage rod and repeat steps 4 and 5 to adjust its length.
7. Remove the spacer inserted between the linkage rod bracket and its stop.
8. Check the backlash by turning the linkage rod bracket of the throttle turntable slightly clockwise. A gap should appear between the bracket and its stop before either throttle lever leaves its stop screw. Gap dimension: 0.062 - 0.094 inch (1.57 - 2.39 mm)
9. Both throttle levers should leave their stops at the same time. Satisfactory synchronization is possible if the second throttle lever moves from its stop after the first throttle lever within a maximum additional increase of 0.030 inch (0.76 mm) in the gap.
10. Release the linkage rod bracket to allow the turntable to return to the closed throttle position. Check that the linkage rod bracket is now in contact with its stop. If any gap is present, repeat steps 1 through 10.

Perform a road test after adjusting the throttle valves and linkage. If the complaint still exists, refer to the diagnostic procedures in the Vehicle Service Manual.