spark plugs MITSUBISHI 3000GT 1994 2.G Workshop Manual

Downloaded from www.Manualslib.com manuals search engine i;ENGINE ELECTRICAL
- Ignition System16-35
OPERATIONl
Turn ignition switch to .“ON”position, and batteryvoltage will be applied to primary winding of
ignition coil.l
When crankshaft position sensor and camshaft
position sensor signal is input to engine control
module, engine control module makes ON-OFF
control of power transistors one by one.l When power transistor is turned on, current
flows from ignition coil (primary winding) to
ground through power transistor.l When power transistor A is turned from ON
to OFF, the spark plugs of No. 1 and No. 4
cylinders spark. Turning of power transistor B
from ON to OFF will produce sparking in spark
plugs of No. 2 and No. 5 cylinders. Furthermore,
when power transistor C is turned from ON toOFF, sparking is produced in spark plugs of
No. 3 and No. 6 cylinders.
TROUBLESHOOTING HINTS1. Engine cranks, but does not start.
(1) Spark is insufficient or does not occur at
all (on spark plug).l Check ignition coil.
l Check camshaft position sensor and
crankshaft position sensorl Check power transistor.
l Check spark plugs.
l Check spark plug cable.
(2) Spark is good.
l Check ignition timing.
2. Engine idles roughly or stalls.
l Check spark plugs.
l Check ignition timing.
l Check ignition coil.
l Check spark plug cable.
3. Poor acceleration
l Check ignition timing.
l Check spark plug cable.
l Check ignition coil.
TSB Revision

Downloaded from www.Manualslib.com manuals search engine 54-164CHASSIS ELECTRICAL - Radio and Tape Player
A-6There is noise when starting the engine.
Noise type
Sounds are in pa-
rentheses ( ).
AM, FM:
Ignition noise
(Popping, Snap-
ping,Cracking,
Buzzing)
Otherelectrical
components
Static electricity
(Cracking, Crin-
kling)
Conditions
0Increasing the engine speedcausing the popping sound tospeed up, and volume de-creases.0Disappears when the ignitionswitch is turned to ACC.
-
lDisappears when the vehicle is
completely stopped.Occurs when parts or wir-
Severe when the clutch is en-ing move for some reasonlgaged.and contact metal parts of
the body.
lVarious noises are produced de-pending on the body part of thevehicle.
Due to detachment from
the body of the front hood,
bumpers, exhaust pipe
and muffler, suspension,
etc.
Causel
Mainly due to the
spark plugs.l Due to the enginenoise.
Noise may appear as
electrical components be-
come older.
Parts to be Location of
inspectedparts
or remedy(next page)
Noise con- 1
denser
Ground
cable2, 3
Repair or replace electricalcomponents.
Return parts or wiring to
their proper position.
Caution
1.Connecting a high tension cable to the noise
filter may destroy the noise filter and shouldnever be done.
2.Check that there is no external noise. Since
failure to do this may result in misdiagnosis
due to inability to identify the noise source,
this operation must be performed.3. Noise prevention should be performed by
suppressing strong sources of noise step
by step.
NOTE
1. Condenser
The condenser does not pass D.C. current, butas the number of waves increases when it
passes A.C. current, impedance (resistanceagainst A.C.) decreases, and current flow is
facilitated. A noise suppressing condenser
which takes advantage of this property is in-
serted between the power line for the noise
source and the ground. This suppresses noiseby grounding the noise component (A.C. or
pulse signal) to the body of the vehicle.
2. Coil
The coil passes D.C. current, but impedance
rises as the number of waves increases relativeto the A.C. current. A noise suppressing coil
which takes advantage of this property is in-
serted into the power line for the noise source,
and works by preventing the noise componentfrom flowing or radiating out of the line.
1 TSB Revision
Ground parts by bonding.
Cases where the problem
is not eliminated by a single
response to one area are
common, due to several
bodypartsbeing
imperfectly grounded.