FBC System Inspection (Colt)

Feed Back Carburetor (FBC) system is composed of various kinds of sensors and actuators and a computer (carburetor control unit) as shown in the system diagram in the preceding page. The FBC system wiring diagram is found at the end of this manual.

INSPECTION OF FBC SYSTEM

If FBC system components (sensors, carburetor control unit-computer, solenoid, etc.) fail, interruption of fuel supply or failure to supply proper amount of fuel for engine operating conditions will result. Therefore, the following situations will be encountered.
(1) Engine is hard to start or does not start at all.
(2) Unstable idle.
(3) Poor driveability. If any of above conditions is noted, first perform basic engine checks (ignition system malfunctions, incorrect engine adjustment, etc.). The FBC system can be checked by use of voltmeter. Inspection procedure is as follows.

Inspection Procedure With the voltmeter, use the diagram on pages 14-30 thru 14-32 (drawing 6FU200) to identify the pin connectors (terminals). Check the voltage of each terminal as specified in the "Output Signals from Tester". Make sure the ignition switch, vehicle operation and conditions are observed as called out in the procedure.






Output Signals from Tester for Engine with 5-speed M/T and A/T






Output Signals from Tester for Engine with 4-speed M/T