Appendix
77
6.5 Common Faults and Troubleshooting
6.5.1 Troubleshooting
Engine faults and analysis
Common Faults
Possible Causes
Fault Inspection and Treatment
1. The engine
cannot be started
1. The natural gas bottle is empty or
the hand valve on gas bottle is not
opened.
2. The gas pressure is too low.
Check the gas pipeline for gas
leak.
Check the gas valve for being
open.
Check the solenoid cut-off valve
is work.
3. There is no sufficient gas intake
Check the air filter and gas
intake system for blockage and
air leak.
4. The start-up rotating speed is too
low (the minimum start-up rotating
speed is 100r/m)
Check whether the battery
voltage can reach 24V.
5. The intake and exhaust valve
adjustment is wrong
Check the valve clearance
according to the operation
manual for engine.
6. The engine control module (ECU) is
damaged.
Replace the ECU.
7. The melted connector clip of oxygen
sensor causes short circuit.
Replace the oxygen sensor.
8. The electronic throttle valve is
broken.
Test the electronic throttle valve
using software.
9. The velocity sensor is in fault.
Check the clearance between
fluted disc and sensor.
10. MAP is broken.
Check the MAP by software.
11. Earth trap wire is loose.
Check the wiring harness is
mounted firmly.
