Fuel Delivery and Air Induction: Testing and Inspection

ON-VEHICLE INSPECTION




1. INSPECT AIR-FUEL RATIO COMPENSATION SYSTEM




a. Measure voltage between terminals of the engine ECM.

CAUTION: Connect test leads from the back side of the connector with the ECM connected.

HINT: Voltage between terminals of the engine ECM is kept constant regardless of the voltage of A/F sensor.

b. Connect the TOYOTA hand-held tester to the DLC3.
c. Select "DATA MONITOR" - "A/FS B1 S1", "A/FS B2 S1" and "O2S B1 S2" to display the monitor.
d. Warm up the A/F sensor with the engine speed at 2,500 r.p.m for approx. 2 minutes.




e. Keep the engine speed at 2,500 r.p.m and confirm that the displays of "A/FS B1 S1", and "A/FS B2 S1" are as shown in the illustration.

CAUTION: The illustration differs from the real display. Only TOYOTA hand-held tester displays the waveform of A/F sensor.

f. Confirm that the display of "O2S B1 S2" changes between 0 V to 1V with the engine speed at 2,500 r.p.m.

2. INSPECT FUEL CUT OFF RPM
a. Increase the engine speed to at least 3,500 r.p.m.
b. Use a sound scope to check for injector operating noise.
c. Check that when the throttle lever is released, injector operation noise stops momentarily and then resumes.