Motive Power Industry BLUR 150, Service Manual

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(8) Start-up normal but idle speed unstable with warm-up finished
General trouble location: 1. Water in fuel; 2. Engine temperature sensor; 3. Spark plug; 4. Air throttle and
idle air bypass; 5. Air intake; 6. ISC; 7. Engine mechanism.
Procedure for general diagnoses:
No. Operating Procedure
Detection
Results
Subsequent Steps
Yes
Repair the air intake
system.
1 Check any jam of the air filter and leakage of the air intake.
No Next step
Yes Next step
2
Check the spark plug and its model and gap conformable to
specifications.
No
Adjustment or
change
Yes Clean relevant parts.
3
Remove the ISC and check the air throttle, the ISCand the idle air
bypass for any carbon deposition.
No Next step
Yes
Correct circuits or
replace any sensor.
4
Press the engine temperature sensor connector and start the engine
to check any instability of the idle speed during warm-up of the
engine.
No Next step
Yes
Change the defective
nozzle.
5
Disassemble the nozzle and check the nozzle leaking or blocked, or
the flow out of tolerance with a nozzle cleaner & analyzer.
No Next step
Yes Change fuel.
6 Check fuel and observe any trouble attributed to fuel just added.
No Next step
Yes
Eliminate any
mechanical trouble
of the engine.
7
Check pressure of the engine cylinder and find any big difference
in pressure.
No Next step
Yes Diagnosis assist
8
Connect an EMS adapter and press the power switch to check
voltages at Pins
1#, 19#, and 29#
; check grounding at Pins
8#
﹐
35
#
and
36#.
No
Repair the relevant
circuits.
33