C 2500 3/4 Ton Pickup 2WD L6-250 4.1L VIN D 2-bbl (1984)
Eagle
Mineral
Washington
Elbert
Moffat
Weld
El Paso
State of Nevada
Carson City
Humboldt
Nye
Douglas
Lander
Pershing
Elko
Lincoln
Storey
Esmeralda
Lyon
Washoe
Eureka
Mineral
White Pine
State of New Mexico
Bernalillo
Lincoln
San Juan
Catron
Los Alamos
San Miguel
Colfax
Luna
Santa Fe
Curry
McKinley
Sierra
De Baca
Otero
Socorro
Grant
Mora
Taos
Guadalupe
Rio Arriba
Torrance
Harding
Roosevelt
Union
Hidalgo
Sandoval
Valencia
State of Utah
Beaver
Iron
Sanpete
Box Elder
Juab
Sevier
Cache
Kane
Summit
Carbon
Millard
Tooele
Daggett
Morgan
Uintah
Davis
Piute
Utah
Duchesne
Rich
Wasatch
Emery
Salt Lake
Wayne
Garfield
San Juan
Weber
Grand
DEALERS AND CUSTOMER INFORMATION
Owners of the 1984 low altitude vehicles taking up permanent residence in one of these high altitude counties, should be encouraged to have these
adjustments performed when vehicles are brought in for service.
After performing these adjustments, dealers should advise customers that, IF THE VEHICLE IS RETURNED TO CONTINUOUS, LOW ALTITUDE
OPERATION, THE ENGINE SHOULD BE RE-ADJUSTED TO LOW ALTITUDE SPECIFICATION PER THE CORRECT CHASSIS SERVICE
MANUAL FOR IMPROVED LOW ALTITUDE. IF RE-ADJUSTED TO LOW ALTITUDE SPECIFICATIONS, THE SUPPLEMENTAL LABEL
SHOULD BE REMOVED.
PROCEDURE I
To be used for all the following 1984 low altitude (NA5) engines used primarily at high altitudes.
Light Duty Federal Emission Packages
^
1.9L and 2.0L Federal
1.
Advance timing to a maximum of 4~ over specification if no or little detonation occurs.
2.
Reset idle speed to specs.
^
5.0L and 5.7L Federal
1.
Advance timing to a maximum of 4~ over specification if no detonation exists.
2.
On vehicles equipped with automatic transmissions, increase choke vacuum break setting from 24~ to 26~. Manual transmission vehicles
do not require adjustment.
3.
Adjust idle speeds to:
