Maintenance Manual for J2 Sedan
Electronic Control System
of Engine
231
Trouble phenomenon 5: Engine speed is normal, but it is difficult to start all the time
General trouble position:
1.
Poor quality of fuel; 2. Fuel injection pump; 3.Coolant temperature sensor; 4.Fuel injector;
5.Ignition coil; 6.Throttle body and idle bypass air passage; 7.Intake passage; 8.Ignition timing;
9.Spark plug; 10.Mechanical part of engine
General diagnosis procedure:
No.
Operating Steps
Detection Results
Subsequent Steps
Yes
Repair air intake
system
1
Check air filter for blockage and intake passage for leakage.
No
Next step
Yes
Next step
2
Connect the fuel pressure gauge (the access point is at the front
end of the induction manifold of the fuel distribution pipe
assembly) to the engine and start the engine to check whether the
reading of fuel pressure gauge at idle condition is at about
260kPa. Disconnect vacuum hose on pressure regulator and
observe whether fuel pressure is about 300kPa.
No
Repair fuel supply
system
Yes
Next step
3
Pull out the high-voltage wire of one of the cylinders and connect
the spark plug to keep the spark plug electrodes about 5mm away
from the engine body, then start the engine to check whether there
is the blue and white high-voltage spark.
No
Repair the ignition
system
Yes
Next step
4
Check the spark plug of each cylinder to observe whether m odel
and gap are in compliance with the specification.
No
Adjust or replace
Yes
Repair the lien or
replace the sensor
5
Pull out the connector of coolant temperature sensor and start the
engine to observe whether the engine is successfully started at this
time.
No
Next step
Yes
Wash throttle and
idling air passage
6
Gently step down the throttle to observe whether it is easy to start.
No
Next step
Yes
Failure of
Replacement
7
Dismantle the fuel injector and check whether there is leakage or
blockage in the fuel injector with cleaning analyzer special for
fuel injector.
No
Next step
Yes
Change fuel
8
Check fuel condition and observe whether the trouble
phenomenon occurs just after adding the fuel.
No
Next step
Yes
Eliminate the
mechanical trouble of
engine
9
Check pressure of all the cylinders and observe whether the
pressure of engine cylinder is insufficient.
No
Next step
Yes
Next step
10
Check whether the ignition sequence of engine and ignition
timing is in line with the specification.
No
Repair the ignition
timing
Yes
Diagnosis help
11
Turn on the ignition switch and check whether the power supply
and earthing are normal.
No
Repair related circuit
