The fuel injection system and throttle body used by the engine already feature fuel circuit
system and fuel-air premixing function. Therefore, the throttle is far less polluted than
traditional throttles. Its simple structure also makes it easier for maintenance. The
cleaning procedure is as follows:
(1) Connect the diagnostic instrument and start up the engine. Stop the engine when
water temperature is above 75℃.
(2) Unfix the air intake pipe connected with the throttle.
(3) Clean away the dust on the throttle body with compressed air (Figure 18-9). Clog the
idle speed bypass hole of the throttle (Figure 18-10) and spray the detergent.
(4) Slightly open the throttle and start and accelerate the engine 5 minutes later. In order
to avoid unstable idle speed or flameout, the throttle may be slightly opened to run the
engine at stable idle speed.
(5) Shut off engine: repeat the above procedure if the dirt is not cleaned away.
(6) Resume the idle speed bypass hole.
(7) Clear off the troubleshooting codes displayed on the diagnostic instrument.
(8) Start the engine and check if it is running normally.
Figure 18-9 Throttle Body
Figure 18-10 Idle Speed Bypass Hole Location
Throttle air intake
side
Idle speed bypass
hole
Five. Maintenance tool
1. Unfixing electrical control system components – unfixing tools for common
mechanical components of vehicle
2. Circuit of the electrical control system and electrical signals of the system – digital
multimteter (with a buzzer);
3. Troubleshooting on electrical control system and checking engine working status;
- Diagnostic instrument for vehicle electrical control system faults (recommended);
4. Fuel pressure gauge, measuring range 0-800kPa