Horizon/TC3 L4-105 1720cc 1.7L SOHC VIN A 2-bbl (1982)
Fig.36. Propane Assisted Idle Speed and Mixture Adjustment
Tampering with the carburetor is a violation of Federal law. Adjustment of the carburetor idle airfuel mixture can only be done
under certain circumstances as explained below. This procedure should only be used if an idle defect still exists after normal
diagnosis has revealed no other faulty condition, such as, incorrect idle speed, incorrect basic timing, faulty hose or wire
connections, etc. It is also important to make sure the combustion computer systems are operating properly. Adjustment of the
air-fuel mixture should also be performed after a major carburetor overhaul.
950 RPM
R-9503A
R-9504A
R-9750A
R-9751A
975 RPM
R-9505A
R-9506A
R-9752A
R-9753A
105ORPM
R-9822A
R-9823A
1100 RPM
R-9824A
R-9825A
R-9937A
R-9938A
(1)
Set the parking brake and place transaxle in neutral. Turn off all lights and accessories. Connect
a tachometer to the engine. Start the engine and allow it to warm up on the second highest step on the fast idle cam until normal operating temperature is
reached. Return engine to curb idle.
(2)
Disconnect and plug the vacuum hose at the EGR valve. Disconnect the vacuum hose to the heated air door sensor at the three way connector, and
in its place, install the supply hose from the propane bottle. Make sure that both valves are fully closed and that the bottle is upright and in a safe
location.
(3)
Unplug the connector at the radiator fan and install a jumper wire so that the fan will run continuously. Remove the PCV valve from the moulded
rubber connector and allow the valve to draw underhood air. Disconnect and plug the 3/16 inch diameter control hose at canister. Connect a
jumper wire between carburetor switch and ground.
(4)
Open the propane main valve, With the air cleaner in place, slowly open the propane metering valve until maximum engine rpm is reached. When
too much propane is added, engine speed will decrease. "Fine tune" the metering valve for the highest engine rpm.
