H2_RECOVERY
03-28-2006, 02:25 PM
Fuel/Ignition - Altitude Performance Adjustments
JANUARY 1984 000 109
1984 JEEP CJ/SCRAMBLER
1E
ENGINE Attention: Workshop, Parts Department.
ALTITUDE PERFORMANCE ADJUSTMENTS
Information
This I.S. Note outlines adjustments for optimum engine performance on 1984 Jeep CJ and Scrambler models being operated at high or low altitudes.
When necessary, perform the engine adjustments outlined in the Adjustment Procedures portion of this I.S. Note. In addition, any CJ/Scrambler model 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 the Milwaukee National Parts Distribution Center.
ADJUSTMENT PROCEDURES
1. 150 C.I.D. FOUR-CYLINDER MODELS WITH MANUAL AND/OR AUTOMATIC TRANSMISSION AND 258 C.I.D. SIX-CYLINDER MODELS WITH AUTOMATIC TRANSMISSION
On the above 1984 six-cylinder and four-cylinder CJ/Scrambler models originally certified for operation at altitudes below 4,000 feet that are being operated above 4,000 feet, the ignition timing must be advanced 7~ and engine idle speed reset. In addition, a jumper wire must be added to the MCU circuit to activate the altitude compensating circuit in the MCU.
1. Remove the tape securing the black with tracer altitude circuit ground wire to the MCU harness.
2. Attach the altitude circuit ground wire to the engine ground screw near the ignition coil.
3. Advance ignition timing 7~ from the setting indicated on the original Vehicle Emission Control Information label and reset engine idle speed to the setting indicated on the same label.
4. Install Vehicle Emission Control Information Update label, part number 8983 100 009, next to the original label.
These adjustments apply to all 1984 Jeep six-cylinder automatic and four-cylinder manual/automatic models originally certified for principal use at altitudes below 4,000 feet. Refer to the Vehicle Emission Control Information label to identify these vehicles.
NOTE: Whenever these vehicles are returned to operation at altitudes below 4,000 feet the MCU circuit jumper wire must be removed, the ignition timing and engine idle speed must be reset to original specifications and the Vehicle Emission Control Information Update label removed.
On 1984 CJ/Scrambler six-cylinder automatic and four-cylinder manual/automatic models originally certified for operation at altitudes above 4,000 feet that are being operated below 4,000 feet, the ignition timing should be retarded 7~ and engine idle reset. In addition, the MCU circuit jumper wire must be disconnected and taped to the MCU harness.
1. Disconnect the black with tracer altitude circuit ground wire from the engine ground screw near the ignition coil. Tape the wire to the MCU harness securely and be sure the wire eyelet is completely covered with tape.
2. Retard ignition timing 7~ from the setting indicated on the original Vehicle Emission Control label and reset engine idle speed to the setting indicated on this same label.
3. Install Vehicle Emission Control Information Update label, part number 8983 100 010, next to the original label.
These adjustments apply to all 1984 CJ/Scrambler six-cylinder automatic and four-cylinder manual/ automatic 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 operations at altitudes above 4,000 feet the MCU circuit jumper wire must be reconnected, 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 MODELS WITH MANUAL TRANSMISSION
On 1984 CJ/Scrambler six-cylinder manual transmission models originally certified for operation at altitudes below 4,000 feet that are being operated above 4,000 feet, the ignition timing must be advanced 7~, engine idle speed reset, and the altitude circuit ground wire in the underhood MCU harness connected to an engine ground screw. In addition, the idle/decel switch must be connected to the carburetor EGR port instead of the spark port.
FIGURE 1 - MODIFYING LOW ALTITUDE MODEL FOR HIGH ALTITUDE OPERATION
1. Untape the black with tracer altitude circuit ground wire from the MCU harness.
2. Attach the ground wire to the engine ground screw near the ignition coil.
3. Reconnect the idle/decel switch to the carburetor EGR port as follows (Fig. 1).
a. Disconnect vacuum line 1 from the idle/decel switch and from tee connector 2 (Fig. 1). Place this line in the glovebox for future reuse - do not discard it.
b. Install cap 813 2325 over the open end of tee connector 2.
c. Cut and install tee connector 321 0891 in vacuum line 3 (Fig. 1). Position the connector about 1-1/4 inches from the EGR-CTO end of the line.
d. Connect 75-inch long vacuum line 4 to the idle/decel switch and to the tee connector in line 3 (Fig. 1).
4. Advance ignition timing 7~ from the setting specified on the original Vehicle Emission Control Information label and reset idle speed to the setting on the same label.
5. Install Vehicle Emission Control Information Update label, 8983 100 009, next to the original label.
These adjustments apply to 1984 CJ/Scrambler six-cylinder manual transmission models originally certified for use at altitudes below 4,000 feet. Refer to the original Vehicle Emission Control Information label to identify these vehicles.
NOTE: Whenever these vehicles are returned to operation at altitudes below 4,000 feet, the altitudes circuit ground wire must be disconnected, the idle/decel switch reconnected to the carburetor spark port, the ignition timing and idle speed reset to original specifications, and the Vehicle Emission Control Update label removed.
On 1984 CJ/Scrambler six-cylinder manual transmission models originally certified for operation at altitudes above 4,000 feet that are being operated below 4,000 feet, the ignition timing must be retarded 7~, engine idle speed reset, and the MCU jumper wire removed. In addition, the idle/decel switch must be connected to the carburetor spark port instead of the EGR port.
1. Disconnect the altitude circuit ground wire from the engine ground screw and tape the wire to the MCU harness. Be sure the wire eyelet is covered with tape.
FIGURE 2 - MODIFYING HIGH ALTITUDE MODEL FOR LOW ALTITUDE OPERATION
2. Connect the idle/decel switch to the carburetor spark port as follows (Fig. 2).
a. Cut and install tee connector 321 0891 in vacuum line 1. Position the connector about 1-1/4 inches from the spark port end of the line.
b. Disconnect vacuum line 2 from tee connector 3. Then reconnect line 2 to the tee connector just installed in vacuum line 1.
c. Plug open end of tee connector 3 with cap 813 2325.
3. Retard ignition timing 7~ from the setting specified on the original Vehicle Emission Control Information label and reset idle speed to the setting on the same label.
4. Install Vehicle Emission Control Information Update label, 8993 100 010, next to the original label.
These adjustments apply to 1984 CJ/Scrambler six-cylinder manual transmission models originally certified for use at altitudes above 4,000 feet. Refer to the original Vehicle Emission Control Information label to identify these vehicles.
NOTE: Whenever these vehicles are retumed to operation at altitudes above 4,000 feet the MCU jumper wire must be reinstalled, the idleldecel switch reconnected to the EGR port, the ignition timing and idle speed reset, and the Vehicle Emission Control Information Update label removed.
Filing Instructions
File this I.S. Note in the plastic binder supplied with your M.R. 252 http://library.alldatapro.com/alldata/LIB~C27368~R0~OB0~P3R0H~N/0/41745968/56418129/56418130/56418132/34853741/34850750/42095789/42504871/56449846/42253686
http://library.alldatapro.com/alldata/LIB~C27368~R0~OB0~P3R0H~N/0/41745968/56418129/56418130/56418132/34853741/34850750/42095789/42504871/56449846/42253687
JANUARY 1984 000 109
1984 JEEP CJ/SCRAMBLER
1E
ENGINE Attention: Workshop, Parts Department.
ALTITUDE PERFORMANCE ADJUSTMENTS
Information
This I.S. Note outlines adjustments for optimum engine performance on 1984 Jeep CJ and Scrambler models being operated at high or low altitudes.
When necessary, perform the engine adjustments outlined in the Adjustment Procedures portion of this I.S. Note. In addition, any CJ/Scrambler model 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 the Milwaukee National Parts Distribution Center.
ADJUSTMENT PROCEDURES
1. 150 C.I.D. FOUR-CYLINDER MODELS WITH MANUAL AND/OR AUTOMATIC TRANSMISSION AND 258 C.I.D. SIX-CYLINDER MODELS WITH AUTOMATIC TRANSMISSION
On the above 1984 six-cylinder and four-cylinder CJ/Scrambler models originally certified for operation at altitudes below 4,000 feet that are being operated above 4,000 feet, the ignition timing must be advanced 7~ and engine idle speed reset. In addition, a jumper wire must be added to the MCU circuit to activate the altitude compensating circuit in the MCU.
1. Remove the tape securing the black with tracer altitude circuit ground wire to the MCU harness.
2. Attach the altitude circuit ground wire to the engine ground screw near the ignition coil.
3. Advance ignition timing 7~ from the setting indicated on the original Vehicle Emission Control Information label and reset engine idle speed to the setting indicated on the same label.
4. Install Vehicle Emission Control Information Update label, part number 8983 100 009, next to the original label.
These adjustments apply to all 1984 Jeep six-cylinder automatic and four-cylinder manual/automatic models originally certified for principal use at altitudes below 4,000 feet. Refer to the Vehicle Emission Control Information label to identify these vehicles.
NOTE: Whenever these vehicles are returned to operation at altitudes below 4,000 feet the MCU circuit jumper wire must be removed, the ignition timing and engine idle speed must be reset to original specifications and the Vehicle Emission Control Information Update label removed.
On 1984 CJ/Scrambler six-cylinder automatic and four-cylinder manual/automatic models originally certified for operation at altitudes above 4,000 feet that are being operated below 4,000 feet, the ignition timing should be retarded 7~ and engine idle reset. In addition, the MCU circuit jumper wire must be disconnected and taped to the MCU harness.
1. Disconnect the black with tracer altitude circuit ground wire from the engine ground screw near the ignition coil. Tape the wire to the MCU harness securely and be sure the wire eyelet is completely covered with tape.
2. Retard ignition timing 7~ from the setting indicated on the original Vehicle Emission Control label and reset engine idle speed to the setting indicated on this same label.
3. Install Vehicle Emission Control Information Update label, part number 8983 100 010, next to the original label.
These adjustments apply to all 1984 CJ/Scrambler six-cylinder automatic and four-cylinder manual/ automatic 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 operations at altitudes above 4,000 feet the MCU circuit jumper wire must be reconnected, 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 MODELS WITH MANUAL TRANSMISSION
On 1984 CJ/Scrambler six-cylinder manual transmission models originally certified for operation at altitudes below 4,000 feet that are being operated above 4,000 feet, the ignition timing must be advanced 7~, engine idle speed reset, and the altitude circuit ground wire in the underhood MCU harness connected to an engine ground screw. In addition, the idle/decel switch must be connected to the carburetor EGR port instead of the spark port.
FIGURE 1 - MODIFYING LOW ALTITUDE MODEL FOR HIGH ALTITUDE OPERATION
1. Untape the black with tracer altitude circuit ground wire from the MCU harness.
2. Attach the ground wire to the engine ground screw near the ignition coil.
3. Reconnect the idle/decel switch to the carburetor EGR port as follows (Fig. 1).
a. Disconnect vacuum line 1 from the idle/decel switch and from tee connector 2 (Fig. 1). Place this line in the glovebox for future reuse - do not discard it.
b. Install cap 813 2325 over the open end of tee connector 2.
c. Cut and install tee connector 321 0891 in vacuum line 3 (Fig. 1). Position the connector about 1-1/4 inches from the EGR-CTO end of the line.
d. Connect 75-inch long vacuum line 4 to the idle/decel switch and to the tee connector in line 3 (Fig. 1).
4. Advance ignition timing 7~ from the setting specified on the original Vehicle Emission Control Information label and reset idle speed to the setting on the same label.
5. Install Vehicle Emission Control Information Update label, 8983 100 009, next to the original label.
These adjustments apply to 1984 CJ/Scrambler six-cylinder manual transmission models originally certified for use at altitudes below 4,000 feet. Refer to the original Vehicle Emission Control Information label to identify these vehicles.
NOTE: Whenever these vehicles are returned to operation at altitudes below 4,000 feet, the altitudes circuit ground wire must be disconnected, the idle/decel switch reconnected to the carburetor spark port, the ignition timing and idle speed reset to original specifications, and the Vehicle Emission Control Update label removed.
On 1984 CJ/Scrambler six-cylinder manual transmission models originally certified for operation at altitudes above 4,000 feet that are being operated below 4,000 feet, the ignition timing must be retarded 7~, engine idle speed reset, and the MCU jumper wire removed. In addition, the idle/decel switch must be connected to the carburetor spark port instead of the EGR port.
1. Disconnect the altitude circuit ground wire from the engine ground screw and tape the wire to the MCU harness. Be sure the wire eyelet is covered with tape.
FIGURE 2 - MODIFYING HIGH ALTITUDE MODEL FOR LOW ALTITUDE OPERATION
2. Connect the idle/decel switch to the carburetor spark port as follows (Fig. 2).
a. Cut and install tee connector 321 0891 in vacuum line 1. Position the connector about 1-1/4 inches from the spark port end of the line.
b. Disconnect vacuum line 2 from tee connector 3. Then reconnect line 2 to the tee connector just installed in vacuum line 1.
c. Plug open end of tee connector 3 with cap 813 2325.
3. Retard ignition timing 7~ from the setting specified on the original Vehicle Emission Control Information label and reset idle speed to the setting on the same label.
4. Install Vehicle Emission Control Information Update label, 8993 100 010, next to the original label.
These adjustments apply to 1984 CJ/Scrambler six-cylinder manual transmission models originally certified for use at altitudes above 4,000 feet. Refer to the original Vehicle Emission Control Information label to identify these vehicles.
NOTE: Whenever these vehicles are retumed to operation at altitudes above 4,000 feet the MCU jumper wire must be reinstalled, the idleldecel switch reconnected to the EGR port, the ignition timing and idle speed reset, and the Vehicle Emission Control Information Update label removed.
Filing Instructions
File this I.S. Note in the plastic binder supplied with your M.R. 252 http://library.alldatapro.com/alldata/LIB~C27368~R0~OB0~P3R0H~N/0/41745968/56418129/56418130/56418132/34853741/34850750/42095789/42504871/56449846/42253686
http://library.alldatapro.com/alldata/LIB~C27368~R0~OB0~P3R0H~N/0/41745968/56418129/56418130/56418132/34853741/34850750/42095789/42504871/56449846/42253687