Diesel Engine - Altitude Performance Adjustments
83olds3SUBJECT NUMBER: 83-T-9
1983 CUTLASS CIERA ALTITUDE PERFORMANCE
ADJUSTMENTS 4.3L V-6 DIESEL ENGINE
DATE: May 16, 1983
1983 Cutlass Ciera models equipped with 4.3L V-6 diesel engines will be manufactured with either high or low altitude diesel emission systems.. Cars equipped with the high altitude emission system will be invoiced with option NA6. The type of system can also be identified by the emission label attached to the fan shroud. The label will indicate that the car was built for primary use at either high or low altitude. These procedures are considered altitude performance adjustments and apply only to in-use vehicles. They should not be used to modify vehicles prior to sale.
CONVERSION OF LOW ALTITUDE SYSTEM TO HIGH ALTITUDE
Dealers in high altitude areas should encourage owners who have moved to high altitude counties to purchase the following adjustment procedure. This adjustment is considered an owner maintenance expense. See attachment for a list of counties which the Environmental Protection Agency has designated as high altitude counties. Diesel timing should be checked or adjusted at the same approximate altitude at which the vehicle will be driven.
FIGURE 1:
1. Replace the EGR vacuum control valve assembly with EGR vacuum control valve assembly part number 22519396 or equivalent. Refer to Figure 1.
2. Remove and discard the vacuum modulator valve, if so equipped, as shown in Figure 1.
FIGURE 2:
3. Reroute the vacuum hoses as indicated in Figure 2.
4. Install Timing Meter J-33075 or equivalent, set pump timing to -6~, and set idle speed to specifications. Turn off engine.
5. Remove air crossover assembly. Install screen covers J-29657.
6. With transmission in Park and A/C off, start engine.
FIGURE 3:
7. Loosen locknut (Figure 3) and slowly turn metering valve stop screw clockwise until idle speed drops approximately 10 RPM.
8. Turn metering valve stop screw counterclockwise 2-1/8 turns. Tighten locknut.
9. Check for fuel leaks around metering valve stop screw.
10. Turn engine off.
11. Remove magnetic tachometer probe and screened covers from intake manifold and reinstall air crossover and air cleaner.
FIGURE 4:
12. Fill in dealer code and date on the supplemental emission control label, part number 14057201 or equivalent (Figure 4). This label must be placed next to the existing underhood emission control information label. Wash off the area with soap and water, dry thoroughly, and apply the new label.
PARTS INFORMATION
Part Part Number
1. EGR Vacuum Control Valve Assembly 22519396 or equivalent High Altitude Application
2. Label 14057201 or equivalent
Suggested Time
The suggested time to perform the High Altitude Adjustment and part replacement is 0.8 hour labor.
CONVERSION OF HIGH ALTITUDE SYSTEM TO LOW ALTITUDE
Dealers should advise owners moving to low altitude areas that they should purchase the following altitude adjustment procedure. This adjustment is considered an owner maintenance expense. Diesel timing should be checked or adjusted at the same approximate altitude at which the vehicle will be driven.
FIGURE 2:
1. Replace the EGR vacuum control valve assembly with EGR vacuum control valve assembly part number 22519395 or equivalent. Refer to Figure 2.
FIGURE 1:
2. Install a vacuum modulator valve, part number 56349 or equivalent, in the location as shown in Figure 1. A rubber block connector, "F" connector and elbow connector will also be required to convert to the low altitude system as shown in Figure 1. Additional vacuum hose may also be required. The part numbers for all parts required are listed in the Parts Section of this bulletin.
3. Reroute the vacuum hoses and install the above parts as indicated in Figure 1.
4. Install Timing Meter J-33075 or equivalent, set pump timing to -6~, and set idle speed to specifications. Turn off engine.
5. Remove air crossover assembly. Install screen covers J-29657.
FIGURE 3:
6. Loosen lock nut (Figure 3) and turn metering valve stop screw counterclockwise 1.5 turns. Tighten lock nut.
7. Start engine. With engine running and transmission in park check for fuel leaks around metering valve stop screw. Turn engine off.
8. Remove magnetic tachometer probe and screened covers from intake manifold and reinstall air crossover and air cleaner.
FIGURE 5:
9. Fill in dealer code and date on the supplemental emission control label, part number 14055121 or equivalent (Figure 5). The label must be placed next to the existing underhood emission control information label. Wash off the area with soap and water, dry thoroughly and apply the new label.
PARTS INFORMATION
Part Part Number
1. EGR Vacuum Control Valve 22519395 or equivalent Assembly - Low Altitude Application
2. Vacuum Modulator Valve 563494 or equivalent
3. "F" Connector 22502326 or equivalent
4. Elbow connector 556992 or equivalent
5. Rubber block connector 560840 or equivalent
6. Vacuum Hose (bulk) 9438381 or equivalent
7. Label 14055121 or equivalent
Suggested Time
The suggested time to perform High to Low Altitude adjustment and part replacement is 0.8 hour labor.
COUNTIES WHICH ARE DESIGNATED HIGH-ALTITUDE AREAS
ARIZONA
Apache Navajo
Cochise Yavapai
Coconino
COLORADO
Adams Kit Carson
Alamosa Lake
Arapahoe LaPlata
Archuleta Larimer
Boulder Las Animas
Chaffee Lincoln
Cheyenne Mesa
Clear Creek Mineral
Conejos Moffat
Costilla Montezuma
Crowley Montrose
Custer Morgan
Delta Otero
Denver Ouray
Dolores Park
Douglas Pitkin
Eagle Pueblo
Elbert Rio Bianco
El Paso Rio Grande
Fremont Routt
Garfield Saguache
Gilpin San Juan
Grand San Miguel
Gunnison Summit
Hinsdale Teller
Huerfano Washington
Jackson Weld
Jefferson
IDAHO
Bannock Franklin
Bear Lake Fremont
Bingham Jefferson
Blaine Lemhi
Booneville Madison
Butte Minidoka
Camas Oneida
Caribou Power
Cassia Teton
Clark Valley
Custer
MONTANA
Beaverhead Madison
Deer Lodge Meagher
Gallatin Park
Jefferson Silver Bow
Judith Basin Wheatland
Powell
NEBRASKA
Banner Kimball
Cheyenne Sioux
NEVADA
Carson City Lyon
Douglas Mineral
Elko Nye
Esmeralda Pershing
Eureka Storey
Humboldt Washoe
Lander White Pine
Lincoln
NEW MEXICO
Bernalillo Mora
Catron Rio Arriba
Colfax Roosevelt
Curry Sandoval
DeBaca San Juan
Grant Sans Miguel
Guadalupe Santa Fe
Harding Sierra
Hidalgo Socorro
Lincoln Taos
Los Alamos Torrance
Luna Union
McKinley Valencia
Otero
OREGON
Harney Lake
Klamath
TEXAS
Jeff Davis Hudspeth
Parmer
UTAH
Beaver Morgan
Box Elder Piute
Cache Rich
Carbon Salt Lake
Daggett San Juan
Davis San Pete
Duschesne Sevier
Emery Summit
Garfield Tooele
Grand Unitah
Iron Utah
Juab Wasatch
Kane Wayne
Millard Weber
WYOMING
Albany Natrona
Campbell Niobrara
Carbon Park
Converse Platte
Fremont Sublette
Goshen Sweetwater
Hot Springs Teton
Johnson Vinta
Laramie Washakie
Lincoln Weston