Mitsubishi Lancer Evolution-IV Workshop Manual page 58

4. PROBLEM SYMPTOMS TABLE
Items
Starting Won't start
Fires up and dies
Hard starting
Idling Rough idle
stability
Hunting
Incorrect idle speed The engine doesn't idle at the usual correct speed.
Engine stall
(Die out)
Engine stall
(Pass out)
Driving Hesitation, Sag
Poor acceleration
Stumble
Shock
Surge
Knocking
Stopping Run on
("Dieseling")
(Figure 1)
Normal
Vehicle
Initial accel-
speed
erator pedal
depression
MPI –
Symptom
The starter is used to crank the engine, but there is no combustion within the
cylinders, and the engine won't start.
There is combustion within the cylinders, but then the engine soon stalls.
Engine starts after cranking a while.
Engine speed doesn't remain constant and changes at idle.
Usually, a judgement can be based upon the movement of the tachometer
pointer, and the vibration transmitted to the steering wheel, shift lever, body, etc.
This is called rough idle or hunting.
The engine stalls when the accelerator pedal is released, regardless of whether
the vehicles is moving or not.
The engine stalls when the accelerator pedal is depressed or while it is being
used.
"Hesitation" is the delay in response of the vehicle speed (engine speed) that
occurs when the accelerator is depressed in order to accelerate from the speed
at which the vehicle is now traveling, or a temporary drop in vehicle speed
(engine speed) during such acceleration. Serious hesitation is called "sag".
(Refer to Figure 1.)
Poor acceleration is inability to obtain an acceleration corresponding to the
degree of throttle opening, even though acceleration is smooth, or the inability
to reach maximum speed.
Engine speed increase is delayed when the accelerator pedal is initially
depressed for acceleration. (Refer to Figure 2.)
The feeling of a comparatively large impact or vibration when the engine is
accelerated or decelerated.
This is repeated forward or rearward surging during constant speed travel or
during variable speed travel.
A sharp sound like a hammer striking the cylinder walls during driving and which
adversely affects driving.
The condition in which the engine continues to run after the ignition switch is
turned to OFF. Also called "Dieseling".
Hesitation
Sag
Time
Troubleshooting
(Figure 2)
Vehicle
speed
Normal
Initial accel-
erator pedal
depression
Stumble
Idling
Time
13-17