JAC J2 User Manual



Maintenance Manual for J2 Sedan
Electronic Control System
of Engine
238
Trouble phenomenon 12: Slow response
of acceleration
General trouble position:
1.
Poor quali
ty of fuel; 2.
Intake pre
ssure sens
or and air
throttle
position s
ensor; 3.Spa
rk plug;
4 .Throttle body and idle bypass air passage; 5.Intake passage; 6.Idle adjustor; 7.Fuel injector;
8.Ignition timing; 9. Exhaust pipe
General diagnosis procedure:
No.
Operating Steps
Detection Results
Subsequent Steps
Yes
Repair air intake
system
1 Check air filter
for
blockage.
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 f
uel distribution
pipe assembly) to the engine and start
the engine to check
whether the reading of fuel pressure gauge when idling is at
about 260kPa. disconnec
t vacuum
hose from pressure
regulator to see whether fuel pressure is about 300kPa.
No
Repair fuel supply
system
Yes
Next
step
3
Check the spark plug of each cylinder to observe whether its
model and gap are in compliance with the
specification.
No
Adjust or repla
ce
Yes
Wash related
components
4
Dismantle the idle adjustor to check whether
there is carbon
deposit in the air throttle body, idle adjustor and idle bypass
air passage.
No
Next step
Yes
Next
step
5
Check whether the intake pressure sensor, air
throttle position
sensor and its circuit are normal.
No
Repair circuit or
replace sensor
Yes
Failure
of
replacement
6
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
7
Check fuel condition and observe w
hether the trouble
phenomenon occurs just after adding the fuel.
No
Next step
Yes
Next
step
8
Check whether the ignition sequence of engine a
nd ignition
timing is in line w
ith the specification.
No
Repair ignition
timing
9
Check
whether
the
operation
of
the
exhaust
pipe
is
smooth.
No
Repair or replace the
exhaust pipe
Yes
Diagnosis
help
10
Turn on the ignition switch and
check whether the power
supply and earthing are normal.
No
Repair related
circuit

JAC J2 Specifications

General

Brand	JAC
Model	J2
Category	Automobile
Language	English