Lifan 620 - Difficult Cold Start

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
5. Difficult cold start
Table 1-55
S/N Operation Test Results Actions
Yes Remove the trouble
1
Turn the ignition switch to ON. Check if there is
trouble information records with a diagnostic
instrument.
No Next step
Yes Next step
2
Check the coolant for normal temperature with a
multimeter (resistance: between XX and XX)
No Replace sensor
Yes Next step
3
Turn on the ignition switch. Connect an adapter
between the ECU and the harness, and check the
voltage of 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
4 Check the air filter for smoothness.
No Replace
Yes Next step
5
After start, check if the pressure of the intake air
manifold at idle speed is between 35kPa and 65kPa.
No
Remove leakage for the air
intake system
Yes
Check throttle and idle
speed passage
6
Gently step on the throttle, and check if the vehicle
can be started easily.
No Next step
Yes Next step
7
Before the engine coolant reaches 35°C, take out the
idle speed actuator connector, and check if the
rotation speed of the engine is decreased.
No Replace idle speed actuator
Yes Next step
8
Connect the fuel pressure gauge valve (the
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
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