General Precautions of EFI System Maintenance
F-100
8. Normal start with unstable idling speed after warming up.
9. Normal start with unstable idling speed or flameout when partly loaded (i.e. with A/C operating).
10. Normal start with high idling speed.
11. Slow rotation or flameout when accelerating.
12. Slow actions when accelerating.
13. Poor acceleration with poor performance.
1. No rotation or slow rotation of engine when started.
General malfunction Locations: 1. Battery 2. Starting Motor 3. Wire Harness or Ignition Switch 4.
Mechanical Part of Engine
General Diagnostic Flow:
S/N Operating Steps Test Result Follow-up Step
1
Inspect the voltage between the two wiring terminals of the
battery using multimeter, and check whether or not it is about
12V when engine is started.
Yes Next Step
No
Battery to be
replaced
2
Keep the ignition switch at the starting position, and use
multimeter to examine whether or not the voltage of wiring
terminal for the positive pole of starting motor is above 12V.
Yes Next Step
No
Wire harness to be
repaired or
replaced
3
Disassemble the starting motor, and examine the working
status of the starting motor. The priority is given to the
inspection of open circuit or being seized arising from bad
lubrication exists.
Yes
Starting motor to
be repaired or
replaced
No Next Step
4
If malfunction happens in winter, it is then required to
examine whether or not it arises from improper selection of
engine lubricant or gearbox oil, leading to excessive
resistance of the starting motor.
Yes
To be replaced
with Lubricant of
proper grade
No Next Step
5
Inspect whether or not the internal mechanical resistance of
engine is too large, giving rise to no rotation or sluggish
rotation of starting motor.
Yes
Engine internal
resistance to be
inspected and
repaired
No
Abovementioned
steps to be
repeated
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