Hisun HS500 Owner's Manual page 165

8-62 Periodic Maintenance and Adjustment
S/N Problems
7 EFI system
Solutions
1. Check if the ECU is broken.
2. Check if the nozzle is clogged or the nozzle to the ECU
connection is disconnected.
3. Check if the engine speed signal sensor is broken.
4. Check if the engine speed signal to ECU connection is
disconnected.
5. Check if the inlet pressure/temperature sensor is
damaged or the ECU connection is disconnected.
6. Check if the throttle sensor is damaged or the ECU
connection is disconnected.
7. Check if the Sub-harness (cable) of the electrical injection
is broken.