Comanche 2WD V6-173 2.8L VIN W 2-bbl (1986)
Air/Fuel Mixture: Adjustments
Before performing idle mixture adjustment, remove idle mixture adjusting screw concealment plug as described under ``Conceal Plug
Removal'' in the ``Carburetor Section''.
Fig. 2 Idle mixture adjusting tool modifications
EXCEPT CALIFORNIA MODELS
The following adjustment should be performed with the air cleaner in place.
1.
Connect suitable tachometer, then start engine and allow to reach operating temperature.
2.
On models with automatic transmission, place selector lever in drive. On models with manual transmission, place selector lever in neutral. Apply
parking brake and block drive wheels.
3.
Check curb idle speed and adjust as necessary, refer to ``Curb Idle Speed, Adjust''.
4.
Using idle mixture socket tool J-29030, modified as shown in
Fig. 2., turn mixture adjusting clockwise until a loss in RPM is noted.
5.
Turn idle mixture adjusting counterclockwise until the highest engine RPM is obtained.
6.
Turn idle mixture adjusting clockwise until a 20 RPM drop in engine RPM is obtained.
7.
If final idle speed differs more than 30 RPM from the original curb idle speed, adjust curb idle speed and repeat steps 4 through 6.
Fig. 2 Idle mixture adjusting tool modifications
CALIFORNIA MODELS
Pre-Set Procedure
1.
Remove carburetor from engine, then idle mixture adjusting screw concealment plug
2.
Turn idle mixture screw clockwise until lightly seated, the back screw out 4 turns.
3.
Check to ensure idle air bleed plug is installed in air horn.
4.
Remove vent stack screen to gain access to lean mixture adjusting screw located in bottom of fuel bowl.
5.
Turn lean mixture adjusting screw clockwise until lightly seated, the back screw out 2-1/2 turns.
6.
Modify tool No. J-29030-B, by grinding 1/8 inch off rear and 1/4 inch off front of tool,
Fig. 2. Install carburetor with modified tool position on
idle mixture adjusting screw.
7.
Leave bowl vent, EGR and canister purge hoses disconnected and cap hose connections carburetor.
8.
Locate hose from carburetor port to to temperature sensor and secondary vacuum break thermal vacuum switch. Disconnect and plug this hose at
temperature sensor on air cleaner.
9.
Connect positive lead of suitable dwell meter to Mixture Control (MC) solenoid dwell test wire (green connector) at carburetor. Connect dwell
meter negative lead to ground, then set meter to 6 cylinder scale.
10.
Connect tachometer to distributor wire (brown connector). If equipped with tachometer, connect test tachometer lead to distributor side of tach
filter.
11.
Place transmission in neutral, with parking brake applied and drive wheels blocked.
Mixture Adjustment Procedure
