Engine - Loading/Runs Rough On Cold Start/Drive Away

Article No. 86-21-12


LOADING/RUNS ROUGH - 5.8L - DURING COLD START/DRIVE AWAY


FORD 1982-87 FORD

LINCOLN-MERCURY 1982-87 MERCURY

CALIBRATIONS: 5.8L 49S Police and Canadian Vehicles

WARNING: This modification is authorized only for the listed engines. Performing this modification on other engine calibrations is unauthorized and could create liability under applicable federal or local laws.

Loading and rough running during cold start and drive away may be caused by fuel vapor entering the choke pulldown cover. This plugs the valve and causes poor choke pulldown control. To correct this procedure, install a new design choke pulldown diaphragm cover and filter using the following service procedure.

1. Remove the choke pulldown diaphragm cover assembly by removing the two retaining screws.

2. Using a straight edge and a pocket scale, measure and record the adjusting screw depth from the mounting surface of the cover assembly. Then scrap the old cover assembly.

3. Obtain choke pulldown diaphragm cover assembly, E1AZ-9B580-A. Measure and set the adjusting screw depth to be the same as recording in Step 2. Then seal the external adjusting screw passage, either with silicone sealer or by plugging with a 1/4 inch lead ball.

4. Inspect the choke pulldown diaphragm and replace if damaged.

5. Install the new cover assembly, E1AZ-9B580-A, and tighten the retaining screws to 15-19 in.lbs. (1-2 N-m).

6. Obtain new fuel separator filter assembly, D4FZ-9C369-A.

7. Install a two-inch long 5/32 ID vacuum hose (DOPZ-12226-B) to the white (distributor) end of the filter assembly. Attach the other end of the two-inch hose to the vacuum nipple on the choke pulldown diaphragm cover assembly.

8. Reroute the original vacuum hose around and under the knock sensor wires. Then attach it to the black (carburetor) end of the filter assembly.

9. Position the filter assembly horizontally with the black (carburetor) vacuum nipple at the bottom (6 o'clock) position and the white (distributor) vacuum nipple at the top (12 o'clock) position.

PART NUMBER PART NAME CLASS

E1AZ-9B580-A Choke Pulldown B
Diaphragm Cover Assembly
D4FZ-9C369-A Fuel Separator Filter WG
Assembly
DOPZ-12226-B
Vacuum Hose AG

OTHER APPLICABLE ARTICLES: Supersedes 85-11-10
WARRANTY STATUS: Reimbursable within the provisions of the Warranty and Policy Manual.
OPERATION: SP9580B86
TIME: 0.5 Hr. DLR. CODING: Basic Part No. 9B580 - Code: J4