Service manual

Information Summary and Preparation 1
22
(12) Acceleration slow
General trouble location: 1. Water in fuel; 2. Inlet pressure sensor and air throttle sensor; 3. Spark plug; 4.
Air throttle and idle air bypass; 5. Air intake; 6. Idle governor; 7. Nozzle; 8. Ignition timing; 9. Exhauster.
Procedure for general diagnoses:
No. Operating Procedure
Detection
Results
Subsequent
Ste
p
s
1 Check the air filter for any jam.
Yes
Check the air
intake system.
No Next step
2
Connect a fuel pressure gauge before the fuel inlet of the
nozzle; start the engine to check the fuel pressure at 300kPa
or so during the idle status.
Yes Next step
No
Repair the fuel
supply system.
3
Check the spark plug in the cylinder and its model and gap
conformable to specifications.
Yes Next step
No
Adjustment or
replacement
4
Remove the idle governor to check the air throttle, the idle
governor and the idle air bypass for any carbon deposition.
Yes
Clean relevant
parts.
No Next step
5
Check the inlet pressure sensor, the air throttle sensor and
circuits.
Yes Next step
No
Correct circuits or
replace any
sensor.
6
Disassemble the nozzle and check any leakage or jam in the
nozzle with a nozzle cleaner & analyzer.
Yes
Replace the
defective nozzle.
No Next step
7
Check fuel and observe any trouble attributed to fuel just
added.
Yes Change fuel.
No Next step
8
Check if the engine’s ignition timing is conformable to
specifications.
Yes Next step
No
Correct ignition
timing.
9 Check the exhauster for exhaust normally discharged.
Yes Next step
No
Repair or replace
the exhauster.
10
Connect an EMS adapter and press the power switch to
check voltages at Pins 5#, 10#, and 23#; check grounding
at Pins 2# and 21#.
Yes Diagnosis assist
No
Repair the
relevant circuits.