Electronic Throttle Control System Test
- Connect a tachometer to engine. Start and run engine until normal operating temperature is obtained. On vehicles without air conditioning, depress and release accelerator. An RPM higher than curb idle speed should be seen for specified time shown in EGR and Throttle Control Specifications table.
- On vehicles equipped with air conditioning, turning the air conditioner on and depressing accelerator for a moment, should give an RPM higher than curb idle speed. Turning the air conditioner off will result in normal idle speed.NOTE: The air conditioning clutch will cycle on and off as it is running. DO NOT mistake this for electronic throttle control operation.
- On all vehicles, if speed increases do not occur as outlined above, turn engine off and disconnect 3-wire connector at carburetor (idle stop solenoid and duty cycle solenoid). Using an ohmmeter, check the resistance of the solenoid by measuring from the 3-wire connector containing the Black wire to ground. Resistance should be 15-35 ohms. If not, replace idle stop solenoid.
- On vehicles without air conditioning, start vehicle and before specified time has elapsed, measure voltage at Black wire of 3-wire connector. Voltmeter reading should equal charging system voltage. If not, replace computer.
- On air conditioned vehicles, start engine and turn air conditioner on. Measure voltage at Black wire of 3-wire connector. Voltmeter reading should equal charging system voltage AFTER specified time has elapsed. If not, check wiring back to instrument panel for an open circuit.EGR and Throttle Control Specifications
Computer Part No. Delay (Seconds) 4145431 90 4145457 60 4145466 20 4145788 60 4145817 90 4145850 60