Choke Plate: Adjustments

Fig. 8 Choke plate pulldown adjustment. Except 1985 - 87 models w/electric choke:

EXCEPT. 1985 - 87 MODELS W/ELECTRIC CHOKE

1. Remove thermostat housing, gasket and retainer.
2. Insert a piece of wire, Fig. 8, into choke piston bore to move the piston down against the stop screw. Maintain light closing pressure on choke plate and measure the gap between the lower edge of the choke plate and air horn wall.
3. To adjust, remove the putty covering the adjustment screw and turn clockwise to decrease or counter-clockwise to increase gap setting.
4. Reinstall choke thermostatic housing, gasket and retainer. Do not tighten screws until Fast Idle Cam Set adjustment has been performed.

Fig. 9 Choke plate pulldown vacuum passage. 1985 - 87 models w/electric choke:

Fig. 10 Removing choke pulldown diaphragm adjusting screw cover. 1985 - 87 models w/ electric choke:

1985 - 87 MODELS W/ELECTRIC CHOKE

1. Remove carburetor from vehicle and cover intake manifold.
2. Place carburetor on work stand suitable to allow access to pulldown diaphragm vacuum passage on underside of throttle body, Fig. 9.
3. Scribe alignment marks on choke cap and choke housing, then remove choke cap, gasket and retainer.
4. Temporarily install choke cap with standard choke cap gasket and align scribe marks, then rotate cap 90° counterclockwise and secure with one screw.
5. Ensuring that choke plate is in fully closed position, actuate choke pulldown motor using an outside vacuum source of at least 17 inches Hg.
6. Using drill gauge of specified size, check clearance between upper edge of choke plate and air horn wall. Gauge should fit in such a manner that it contacts air horn and choke plate but does not move plate.
7. If adjustment is necessary, carefully remove diaphragm adjustment screw cap using suitable tool, Fig. 10.
8. Using 5/64 inch Allen wrench, turn adjustment screw clockwise to decrease setting or counterclockwise to increase setting. Maintain a minimum of 17 inches Hg. to pulldown diaphragm during adjustment. Cycle vacuum from 0 to 17 inches Hg. to verify setting.
9. Apply suitable sealant to adjustment screw cavity and check fast idle cam adjustment.