High Altitude Driveability Modifications
Article No: 82-11A-8June 4, 1982
Subject:
Modification Of Sea Level Calibrations For Altitude Applications
Light Trucks
1982 F-1OO Trucks with 3.8L Engines
Calibration: 2-55D, AND 2-56D.
Warning:
This Modification Is Authorized Only For The Listed Engines. Performing This Modification On Other Engines Is Unauthorized And Could Create Liability Under Applicable Federal Or Local Laws.
Customers who may have relocated and/or continually operate the subject vehicles in high altitudes (above 4,000 ft.) may have the following procedure performed to improve performance:
On a customer concern basis to convert the above calibrations to altitude, proceed as follows:
1. Remove and retain the accelerator pump rod assembly (E1PE-9F687-BA) and install a new E1PZ-9F687-A assembly. Refer to Group 24 (Carburetor) 1982 Truck Shop Manual.
Figure 5:
Figure 6:
2. Remove the pullover air bleed (9A521) from the top front of air horn (Figure 5 and Figure 6). Use a small plug remover or a sheet metal screw of suitable size.
3. On 2-55D only - remove choke plate lever (9551) screw - reposition the rod to the altitude hole and reinstall screw.
4. Advance initial timing 6 ° from specification on Vehicle Emission Decal.
NOTE:
After this adjustment, unacceptable detonation may be experienced if the vehicle is operated at sea level.
5. Remove and discard existing C4 transmission vacuum diaphragm (D6AP-7A377-AA) and attaching clip. Install an altitude compensating diaphragm (D7DZ-7A377-A) and attaching clip (D8BZ-7F006-A) as outlined in the 1982 Light Truck Chassis Manual. Vacuum hose should be cut to fit.
NOTE:
Step 5 does not apply to manual transmission vehicles.
6. Check/adjust engine idle speed as necessary.
7. Obtain a Vehicle Emission Control Information Update Label (available at all Ford or Lincoln-Mercury dealers) and fill in the appropriate information as indicated on page 2.
8. Parts removed and obtained should be returned to the customer in the event the vehicle is returned to continuous sea level operation.
If the vehicle is returned to continuous sea level (below 4,000 ft. alt.) operation, the Vehicle Emission Control Information Label should be removed and the following procedure followed:
1. Replace the accelerator pump rod with E1PZ-9F687-A assembly retained from Step 1.
2. Install a E2TZ-9A521-A (.033) pull-over air bleed into the pullover tube hole at the top front of the air horn. (Previously removed in Step 2). Use a 1/4" drift punch - tap lightly.
3. Remove the choke plate lever screw and reposition the rod to non-altitude (STD) hole - and reinstall screw - on 2-55D only.
4. Reset initial ignition timing to specification on Vehicle Emission Decal.
NOTE:
The C5 Transmission Vacuum Diaphragm is self-compensating and does not require replacement.
5. Check/adjust engine idle speed as necessary.
6. Remove the Vehicle Emission Control Information Update Label.
Parts Block
Warranty Status: Reimbursable within the provisions of the Warranty and Policy Manual.
Operation: SP 9687-A-82
Time: 0.9 Hr.
DLR. Coding:
Basic Part No. Code:
LO5 53
PROGRAM CODE: LOS (The program code is to be entered in the Program Code Box on the Warranty Claim Form 1863.)