FUEL INJECTOR BALANCE TEST
Note. Allow engine to cool to avoid irregular readings due to "hot soak" fuel boiling. To prevent flooding, INJECTOR BALANCE TEST should not be repeated more than once without starting and running engine.
The injector balance test is used to pulse the injector for a precise amount of time, spraying a measured amount of fuel in the intake manifold. As each injector is pulsed, a drop in fuel rail pressure occurs. This pressure drop can be recorded and compared to other injectors. An injector with a pressure drop of 1.5 psi (10 kPa) or more, greater than or less than other injectors, should be considered faulty.
Malfunction Indicator Light Diagnosis (MIL) No Light
See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK in BASIC TESTING article.
A/C ON Switch/System Test
- Turn ignition switch to RUN position. Move mode selector switch to any position other than OFF position. With A/C control assembly connected, measure voltage between mode selector switch and ground. For wiring schematics, see appropriate WIRING DIAGRAMS article.
- Battery voltage should be present. If battery voltage is present, mode selector switch is operating normally. If battery voltage is not present, check wire from mode selector switch to fuse for an open circuit. Also check A/C high and low pressure switches for an open.
- Check voltage between mode selector switch wire and ground. Voltage should not be present. If voltage is present, replace mode selector switch.
Compressor Clutch Control Circuit Diagnosis
See appropriate AIR CONDITIONING & HEATING section for diagnosis.
