Geely CK MR479Q 2007, Workshop Manual

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71
3. Poor acceleration
(1) Symptom
Engine speed can not be increased immediately after depressing the accelerator pedal, there is
time lag,and the acceleration reaction is delayed or there is slight fluctuation during the acceleration.
(2) Causes and Troubleshooting
a. There is fault in throttle position sensor, repair or replace it;
b. Poor intake system seal, repair it;
c. There is low fuel pressure, troubleshoot it;
d. Poor injector operation, clean or replace it;
e. Intake pressure temperature sensor fault, repair or replace it;
f. Check valve is damaged and shall be replaced;
g. Ignition advance angle is not correct and shall be adjusted;
h. Fuel pressure regulator is damaged and shall be replaced;
i. Air cleaner is clogged and shall be cleaned or replaced;
(3) Diagnosis procedure for poor acceleration (Figure 151)
Figure 151
Poor acceleration
Check the air tightness of the intake air system
Poor seal
Repair
OK
Check whether the air cleaner is clogged
Clogged
Clean or replace
OK
Check the throttle valve position sensor for failure
Abnormal
Repair or replace
OK
Check the fuel pressure
Abnormal
Service the electric fuel pump,
fuel filter and fuel pressure regulator
OK
Check whether the injector inject properly
at idle and maximum load
NG
Replace
OK
Check whether the check valve and EVAP are faulty
Yes
Repair or replace
OK
Check whether the vacuum pressure sensor is OK
NG
Replace
OK
Adjust a ECU to retry