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 0V 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.