Lifan 620. Manual — part 17

Table 1-52 (Continued)

S/N Operation Test

Results

Actions

Yes

Replace or repair fuel intake

pipe

15

Check the fuel intake pipe for leakage or blockage.

No

Replace fuel pump

Yes

Repair or replace fuel return

pipe

16

Check if the fuel return pipe is blocked or bent.

No

Replace fuel pressure

regulator

1

2

Yes Next

step

3

Disconnect the fuel pipe, and turn the ignition switch.

Check if the pressure of the fuel system still keeps

between 150kPa and 200kPa after 1 hour.

No

Repair fuel system leakage

Yes

Replace fuel pressure

regulator (inbuilt)

4

Connect the fuel pipe. Block the fuel return pipe, and

turn off the fuel pressure gauge valve. Turn off the

ignition switch. Check if the pressure of the fuel

system still keeps between 150kPa and 200kPa after

1 hour.

No Next

step

69

Table 1-53 (Continued)

S/N Operation Test

Results

Actions

Yes

Replace fuel injector and fuel

pipe

5

Check the fuel injector and the fuel pipe for leakage.

No Next

step

Yes

Check the coolant

temperature and line

6

Take out the water temperature sensor, and start the

engine. Is the engine OK?

No Next

step

7

8

9

1

instrument.

Yes Next

step

2

Check the air filter for smoothness.

No Replace

Yes Next

step

3

After successful start, check if the intake air manifold

pressure is between 35 kPa and 65kPa at idle speed.

No

Remove leakage for the air

intake system

4

Gently step on the throttle, and check if the vehicle

can be started easily.

Yes

Check and replace throttle

and idle speed passage

70

Table 1-54 (Continued 1)

S/N Operation Test

Results

Actions

Yes Next

step

5

Connect the fuel pressure gauge valve. Short-circuit

the pin 30 and the pin 87 of the fuel bump relay, and

run the fuel pump. Check if the fuel pressure is about

300kPa.

No 9

Yes 8

6

Connect the battery and the fuel injector with a special

connector. With the voltage supply of 12V, check the

fuel injector for normal operation.

No Next

step

7

8

9

15

the following pins of the ECU. Is the voltage of the pin

J1-12 (crankshaft position sensor) is about 12V? Is

the empty pin and the pin J1-54 (idle speed stepper

motor A+) is 0V?

No

Check harness and interface

Yes Next

step

16

Keep the engine at idle speed. After the coolant

reaches normal temperature, ground the pin 51 of the

ECU with a short-connected line. Check if the ignition

advance angle is a 6.75° crank angle.

No

Adjust ignition advance

angle

71

Table 1-54 (Continued 2)

S/N Operation Test

Results

Actions

Yes Next

step

17

Check if the compressed pressure of the engine

cylinder is normal.

No

Remove the trouble

Yes

Repair or replace

18

Check if the intake air manifold absolute pressure and

temperature sensor is blocked.

No Next

step

Yes Replace

ECU

19

Check if the coolant temperature sensor for normal

operation.

No

Repair or replace

1

2

3

4

5

6

7

8

connection point is related to the vehicle model).

Carry out direct grounding for the pin 86 of the fuel

pump relay. Turn on the ignition switch and run the

fuel pump relay and fuel pump. Check if the fuel

pressure is between 250kPa and 300kPa.

No 12

Yes 11

9

Connect the battery and the fuel injector with a special

connector. With the voltage supply of 12V, check the

fuel injector for normal operation.

No Next

step

72