Hisun HS800 - Fuel System Diagnosis

Engine Management System
7-10
Fuel System Diagnosis
Step
Action
Yes
No
1
Switch on Ignition
key. Fuel Pump
primes for 3
seconds when the
ignition key is ON.
Check for fuel pump
running noise for 3
seconds after
ignition key is ON.
If fuel pump running
noise can be heard,
go to step 4.
If fuel pump running
noise can not be
heard, go to step 2.
2
Disconnect fuel
module coupler.
Check voltage at
the harness coupler.
Is the voltage within
10-14V ?
Go to step 3 Check the electrical
circuit from Ignition
to fuel module.
3
Connect 12V DC
power supply
(battery) to fuel
module.
Make sure that
enough fuel
available in fuel tank
to avoid fuel pump
running dry. Is the
fuel pump running
1. Check electrical
circuit from fuel
module to ECU
2. Check ECU
1. Check Fuel
Pump Harness
Integrity
2. Check Fuel
Pump
4
Check fuel system
pressure at Injector
inlet (with a T-joint)
while engine is
running in idle
condition.
Is the pressure
between 220-
270kPa?
Fuel Module
Operation
Normal
Go to Step 5
5
Is the Pressure
below 220kPa?
1. Check for leaks
from hoses hose
joints
2. Check Fuel Pump
3. Check Pressure
Regulator
1. Clogged Filter
2. Kink or Blockage
in Fuel Hoses
3. Check Regulator