Propane Idle Set - Procedure

84chrysler8

Models


1981-1982-1983 Domestic Front Wheel Drive Vehicles With 2.6L MMC Engine - Federal, California & Canada Emission Systems


Subject


Propane Idle Set Procedure


Index


FUEL


Date February 13, 1984


No..

14-06-84


P-498-C
The propane idle set procedure is authorized for 1981-1982-1983 subject model domestic vehicles with 2.6L MMC engines.

The propane idle set method is to be used when "CO" meter procedures cannot be used, i.e., "CO" meter in for repairs or is not available in the service area.

PROPANE IDLE CHECK & SET PROCEDURE

IMPORTANT: BEFORE CHECKING OR ADJUSTING ANY IDLE SPEED, CHECK BASIC IGNITION TIMING AND ADJUST IF NECESSARY, USING THE PROCEDURE OUTLINED IN THE RESPECTIVE MODEL YEAR SERVICE MANUAL.

1. Set parking brake and place transaxle in neutral. Turn off all lights and accessories. Connect a tachometer to the engine. Run engine until full operating temperature is reached.

2. Disconnect cooling fan and allow engine to idle for two minutes. Remove fresh air duct from air cleaner snorkel. Insert propane supply hose into air cleaner snorkel opening 4 inches. Make sure that both valves are fully closed and that the bottle is upright and in a safe location.

3. Open the main propane valve. Slowly open the propane "Fine" control valve until maximum engine rpm is reached. (Too much propane or too rich idle mixture will cause the engine to loose rpm as the fine control valve is opened.)

4. Note the engine rpm increase. The specified values of the engine rpm increase above curb idle as shown on the VECI label are as follows:

Federal & California 25-75 rpm
Canada 50-100 rpm

If the engine rpm increase is not within the above specifications, proceed to the next step.
If the engine rpm increase is acceptable, turn off both valves on the propane bottle. Remove propane suppy hose and reinstall the fresh air duct to the air cleaner. Reconnect cooling fan. Remove tachometer.

5. To be performed only if the engine rpm increase is not within the above specifications.

It is not necessary to remove carburetor from intake manifold to remove the idle mixture screw plug.

A. Remove impact plate if so equipped.

B. Drill out concealment plug on carburetor. Remove vacuum connector from high altitude compensator (HAC) fittings on carburetor air horn if so equipped.

FIGURE 1 - TYPICAL CARBURETOR EXAMPLE:

C. Use a 1/4" diameter drill 8" long at the 11 o'clock position on the plug boss (Figure 1).

Plug should pop out when the drill bit contacts it.
D. Run engine until full operating temperature is reached.

E. Disconnect cooling fan and allow engine to idle for two minutes.

FIGURE 2 - IDLE SPEED ADJUSTMENT:

Open the propane main valve. Slowly open the propane "Fine" control valve until maximum engine rpm is reached. With propane still flowing, adjust the idle speed screw to get the specified propane rpm from specifications below (Figure 2):
PROPANE IDLE SPECIFICATIONS

Curb Idle RPM Propane RPM

Federal & 800 850
California

Canada 800 875

F. Turn off propane main valve and allow engine speed to stabilize. Slowly adjust the idle mixture screw to achieve the curb idle rpm specified above (Figure 1).

G. Turn on the main propane valve. Adjust the "Fine" control valve to again get the highest engine rpm. If the maximum engine speed is more than 25 rpm different than the specified propane rpm, repeat Steps E through G.

H. Turn off both valves on propane bottle. Remove propane supply hose and reinstall the fresh air duct to the air cleaner. Reinstall the concealment plug (PN MD606523) and, if removed, reinstall the steel impact plate on intake manifold and reconnect cooling fan.

FIGURE 3 - IDLE UP ADJUSTMENT:

6. If equipped with air conditioning, set the temperature control lever to the coldest position and fan on low speed and turn on air conditioning. With the compressor running (clutch engaged), set the engine speed to 900 rpm by turning the idle up adjusting screw (Figure 3).

POLICY: Reimbursable within the provisions of the warranty


TIME ALLOWANCE:
Labor Operation No. 14-30-06-94................... 0.6 Hrs.


FAILURE CODE: RO - Driveability XX - Service Adjustment