CJ-7 L4-150 2.5L VIN U 1-bbl (1983)
Idle Speed: Technical Service Bulletins
Engine - Altitude Performance Adjustments
AUGUST 1983 000 061
1983 JEEP VEHICLES
11E
ENGINE
Attention: Workshop, Parts Department.
ALTITUDE PERFORMANCE ADJUSTMENTS
Information
This I.S. Note provides information on improving the performance of 1983 Jeep vehicles being operated at altitudes above or below that which the
engine was originally certified for and adjusted to.
When necessary, perform the engine adjustments outlined in the Adjustment Procedures portion of this I.S. Note. In addition, any Jeep vehicle that is so
adjusted must have a unique Emission Control Information Update label installed. The part numbers for these unique labels are provided in the following
Adjustment Procedures.
The adjustment procedures and unique labels must be made available at no cost to independent repair facilities and the general public. A notification is
also provided in current owner's manuals to make customers aware of these adjustments. The Emission Control Information Update labels and technical
information are available through our distribution facility:
Distribution Services 37200 Amrhein Road Livonia, Michigan 48150
ADJUSTMENT PROCEDURES
1.
2.5 LITER FOUR-CYLINDER MODELS
2.
SIX-CYLINDER AND 2.46 LITER FOUR-CYLINDER MODELS
3.
EIGHT-CYLINDER MODELS
1.
2.5 LITER FOUR-CYLINDER MODELS
On 1983 2.5L four-cylinder Jeep models originally certified for operation at altitudes below 4,000 feet that are being operated above 4,000 feet, the
ignition timing, as shown on the Vehicle Emission Control Information label in the engine compartment, should be advanced 7~ and the engine idle
speed should be reset to the specification shown on the same label.
1.
Advance ignition timing 7~ from the setting specified on the original Vehicle Emission control Information label and reset engine idle speed to the
setting indicated on the same label.
2.
Install Vehicle Emission Control Information Update label, part number 89 83 100 009, next to the original label.
These adjustments apply to all 1983 2.5L four-cylinder Jeep models that were originally certified for principal use at altitudes below 4,000 feet. Refer to
the Vehicle Emission Control Information label in the engine compartment to identify these vehicles.
NOTE:
Whenever these vehicles are returned to operation at altitudes below 4,000 feet, the ignition timing and engine idle speed must be reset to
original specifications and the Vehicle Emission Control Information Update label removed.
On 1983 2.5L four-cylinder Jeep models originally certified for operation at altitudes above 4,000 feet that are being operated below 4,000 feet, the
ignition timing as shown on the Vehicle Emission Control Information label in the engine compartment, should be retarded 7~. The engine idle speed
reset to the specifications shown on the same label.
1.
Retard the ignition timing 7~ from the setting specified on the original Vehicle Emission Control Information label and reset engine idle speed to
the setting indicated on this same label.
2.
Install Vehicle Emission Control Information Update label, part number 89 83 100 010, next to the original label.
These adjustments apply to all 1983 four-cylinder Jeep models that were originally certified for principal use at altitudes above 4,000 feet. Refer to the
Vehicle Emission Control Information label in the engine compartment to identify these vehicles.
NOTE:
Whenever these vehicles are returned to operation at altitudes above 4,000 feet the ignition timing and engine idle speed must be reset to
original specifications and the Vehicle Emission Control Information Update label removed.
2.
SIX-CYLINDER AND 2.46 LITER FOUR-CYLINDER MODELS
On 1983 six-cylinder and 2.46L four-cylinder Jeep models originally certified for operation at altitudes below 4,000 feet that are being operated above
