Page 523 - Foton Workshop Manual - Tunland (AT)

DIAGNOSTICS - ENGINE CONTROL SYSTEM 04-377

3 . Check the throttle body
(a) Check whether the throttle has oil and carbon deposition is stuck or not, the air intake
channel around the throttle has oil and carbon deposition or not.
(b) Start the motor, idling rotation.
(c) Use a diagnostic tool, perform the throttle test.
(d) When the diagnostic tool controls the throttle rotation, the motor speed can have high 04
or low changes simultaneously.
(e) Unplug the throttle connector, measuring connector terminal should be 12V voltages.
(f) When turn off the ignition switch, depress and release the accelerator pedal to check
the throttle rotates or not.

Is the inspection result normal?
YES>To step 4.

No > Clean, fix or change the harness, connector or throttle valve.

4 . Check high pressure fuel pump actuator circuit
(a) Ignition switch: OFF.
(b) Disconnect the battery negative cable.
(c) Check whether high pressure fuel pump actuator circuit can work properly.

Is the inspection result normal?
YES>To step 5.

NO >Repair or replace fuel pump actuator wire harness.

5 . Check the fuel injector
(a) Unplug the injector connector.
(b) Remove the fuel distribution pipes and injector outside the engine together.
(c) Add the battery voltage of 12 V directly to the injector.
(d) Every injector shall inject the fuel according to the standard flow and have uniform
atomization.

NOTICE
When check the injection status of the injectors, the fuel amount the four cylinder
injectors spraying differs largely in the same conditions, then it should change the
injector. Check whether the injector nozzle has colloidal substances or not, if it has,
it may use cleaning agent to soak and spray, or it may cause the insufficient of fuel
or bad acceleration etc.

DANGER
When testing the fuel system:

• Place a note with "Caution: Flammable" in the work area.
• Must work in a well ventilated area and with a carbon dioxide extinguisher.
• Smoking is strictly prohibited when working on the fuel system. Work areas
should be away from open flames and sparks.
• Put the fuel in an explosion proof container.

Is the inspection result normal?

Page 523