Jeep 1987 Wrangler Workshop Manual page 1148

5
These adjustments apply to 1985 Eagle/Jeep,
49-State/California/Canada 4.2L models with
automatic transmission originally sold 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 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.
49-State/California/Ganada 4.2L Engine
Adjustment - Manual Transmission
On 1985 Eagle/Jeep, 49-State/California/
Canada 4.2L models with manual transmission
originally sold 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 a jumper wire
added to the MCU circuit. In addition, the idle/
decel switch must be connected to the
carburetor E G R port instead of the spark port.
1. Move the carpeting away from the passenger
front s e a t toeboard to e x p o s e the M C U
harness.
2. Untape the two-terminal connector from the
M C U harness.
3. Connect jumper wire, P/N 318 6890, to the
two-terminal c o n n e c t o r and reinstall the
carpet.
4. C o n n e c t t h e i d l e / d e c e l s w i t c h to the
carburetor E G R port a s follows (Fig. 1).
a. Disconnect vacuum line 1 from idle/decel
switch and from tee connector 2 (Fig. 1).
Place this line in the glove box - do not
discard it.
b. Install cap, P/N 813 2325, over the open
end of tee connector 2.
c. Cut and install tee connector, P/N 321
0891, in vacuum line 3 (Fig. 1). Position the
connector about 1 % inches from the E G R -
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).
5. Advance ignition timing 7 ° from the setting
indicated on the original Vehicle Emission
Control Information label in the e n g i n e
compartment and reset engine idle s p e e d to
the setting indicated on the s a m e label.
6. Install Vehicle Emission Control Information
Update label, P/N E F 8980 000 743, next to
the original label.
T h e s e adjustments apply to 1985 Eagle/Jeep,
49-State/California/Canada 4.2L models with
manual transmission originally sold for u s e 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 M C U jumper wire must be
r e m o v e d , the i d l e / d e c e l s w i t c h r e -
connected to the carburetor spark port,
the ignition timing and idle speed reset
to original s p e c i f i c a t i o n s , a n d the
Vehicle Emission Control Update label
removed.