SUZUKI GRAND VITARA 1987 Service Repair Manual

SECTION 8
IGNITION SYSTEM
CONTENTS
8-1. GENERAL DESCRIPTION...................................8-2
DISTRIBUTOR..........................................8-3
IGNITION COIL........................................
SPARK PLUG...........................................8-4
8-2.MAINTENANCE SERVICE................................. . .8-5
HIGH TENSION CORD.....................................8-5
SPARK PLUG............................................ . . 8-5
IGNITION COIL..........................................8-5
DISTRIBUTOR..........................................8-5
IGNITION TIMING....................................... .8-9
DISTRIBUTOR DRIVE GEAR............................... .8-10
8-3.IMPORTANT REMINDERS FOR INSTALLATION.............. . 8-11
DISTRIBUTOR......................................... . .8-11
8-4
8
8-1

8-l. GENERAL DESCRIPTION
The ignition system is of contact-pointless type (full-transistorized type).
The principal components of the ignition system are spark plugs, ignition coil, and distributor. The distri-
butor has a rotor, an ignitor, a signal generator, a vacuum advancer and a centrifugal advancer.
The signal generator is to generate the ignition signal and consists of a signal rotor, a magnet and a pickup
coil. The signal rotor is attached to the distributor shaft, and the magnet and the pickup coil are attached
to the generator base plate.
When the distributor shaft rotates, the magnetic flux passing through the pickup coil varies due to the
change in air gap between the pickup coil and the signal rotor. As a result, the alternating current voltage
is induced in the pickup coil. The voltage induced turns on and off the ignitor which switches off the
ignition coil primary current. Thus, the high voltage is induced in the secondary winding of ignition coil
and ignition sparks are generated at the spark plugs.
The distributor is a sort of rotary switch, whose rotor connects the four plugs, one at a time, to secondary
winding of the ignition coil through the wires called “high-tension” cords. Note that there are one high-
tension cord, from secondary winding to the center of the distributor cap, and four more high-tension
cords between the spark plugs and the four terminals on the cap.
NOTE:
Whereabouts of terminal connections are clearly indicated in the diagram below. When inspecting the
electrical wiring, refer to this diagram and check to be sure that each connection is tight Examine the
cords for torn insulation and for evidence of groundinq
8
r
6541
1.Spark plug2.Distributor3.Distributor rotor4.Signal rotor
5.Generator6.lgnitor7.Ignition coil8.Ignition switch
9.Battery
Fig. 8- 1
8-2

Distributor
1.Vacuum ControlJer2.Distributor cap
3.
Seal4. Distributor housing
5. Distributor driven gear
6.
Pin
7.
O-ring
8. Rotor
9. Signal generator dust cover
10. lgnitor dust cover
11. Signal generator
12. lgnitor
13. Generator base plate
14. Signal rotor
Fig. 8-2
[Timing advancer] [Vacuum advancer]
The distributor shaft, from its driven-gear end to
the rotor-carrying end, is not a single solid piece;
actually this shaft is in two pieces connected
together through the timing advancer. The
advancer is essentially a flyweight mechanism.
Timing advancing action is accomplished by
twisting the top shaft piece relative to the bot-
tom one in the direction of shaft rotation.
The single rotor is mounted on the top piece.
The twisting movement is produced by the
speed-dependent radia I (or spreading) move-
ments of the two flyweights.
In this vacuum-advance mechanism, when the
vacuum in the carburetor gets high, the pressure
acting on the diaphragm overcomes the spring
force in it and the controller rod attached to the
diaphragm is pulled. And the rod so pulled turns
the generator base plate counter to the direction
of the distributor shaft rotation (counterclock-
wise) to advance (quicken) the ignition. (Before
advanca)
(After advance)
Base
C
/ -Vacuum DiaphragTI
spring
Fig. 8-3
weight
Fig. 8-4
8-3

Ignition Coil
The ignition coil is a sort of miniature transfor-
mer and, as such, has an iron core around which
two coils are wound- primary and secondary
windings mentioned above. The two are so close
to each other that a sudden change in themagnetic flux produced by “primary current”
flowing in primary winding (in a less number of
coil turns) induces a very large electromotive force (voltage) in secondary winding (in a
greater number of coil turns). These live parts
are housed in a tight, insulator case topped by the cap. Note that the cap has three terminals:
one high-tension terminal and two low-tension
terminals.
High-tension terminal
Primary terminal
lt-
Case
It
Primary winding
II
Secondary winding
j- Core
m2 I,,,insulator
Fig. 8-5
Spark Plugs
Each new machine shipped from the factory is
fitted with standard plugs.
Copper core
Center electrode
Fig. 8-6 Insulator
Standard typeCold type
NGKBPRdESBPR-6ES
Nippon DensoWlGEXR-UW’LOEXR-U
8-4

8-2. MAINTENANCE SERVICEIgnition Coil
High Tension Cords
Check cord terminals for corrosion, breaks and
distortion, and cords for crack or deterioration.
Replace cord as necessary.
NOTE:
DO NOT bend or pull high tension cords to avoid
inside damage. Grip rubber boot when removing
orinstalling cords.
1. Rubber boot2. High tension cord
Fig. 8-7
Spark Plugs
Check following:
l Electrode wear
l Carbon deposits
l Insulator damage.
If any fault is found, replace plugs.
Check gap, and make sure that gap is within
specification. If gap is out of specification,
adjust it by bending ground (side) electrode.
I
Plug gap “A”0.7 - 0.8 mm
(0.027 - 0.031 in.)
Disconnect negative cable at battery. Disconnect
lead wires and high tension cord from ignition
coil. Remove ignition coil, and check it as
follows.
Measure primary coil resistance.
Using ohmmeter, measure resistance between
positive @ and negative @ terminals.
Primary coil
resistance1.35- 1.65D
Measure secondary coil resistance.
Using ohmmeter; measure resistance between
positive @ terminal and high tension terminal.
I
Secondary coil
resistanceI11.0 - 14.5 kSZ
I
NOTE:
Take readings when coil is about 20” C (66” F).
Fig. &9
Reverse removal procedure for installation.
When reinstalling, make sure that each connec-
tion is tight.
Distributor
[Distributor cap]
Leakage of high-tension energy for ignition
shows up as misfiring in the engine. It occursat
any part of the high-tension line where insula-
tion has failed or in a dirty distributor cap, that
is, an internally dirty cap.
A wider spark gap in the plug, a condition often
found in poorly cared spark plugs, promotes a
tendency of high-tension energy to find a short-
cut to ground.
Fig. 8-8
8-5

Cleanliness is very important for the distributor
cap. With a clean dry cloth, wipe off dust or
grime, if any, and inspect for any damaged
(scarred, scratched or cracked) part or any part
evidencing high-tension leakage inside the cap.
Be sure to replace such parts.
[Signal rotor air gap]
Signal rotor air gap0.2 - 0.4 mm
(0.008 - 0.016 in)
Check air gap and adjust it as necessary.
1. Remove distributor cap and rotor.
2. Using thickness gauge, measure air gap bet-
ween signal rotor tooth and generator.
1. Signal rotor
2. Generator
3. Signal rotof air gap
Fig. 8-l 1
3. If air gap is out of specification, adjust it.
Remove distributor and then ignitor.
Loosen 2 screws securing generator.
Using blade (-) screwdriver, move generator
and adjust air gap to specification.
1. lgnitor
2. Generator
3. Generator screw4. Signal rotor air gap5. Blade screwdriver
Fig. 8-12
After adjustment, tighten 2 screws and
recheck air gap. Install ignitor, rotor and
distributor cap.
Install distributor referring to p. 8-11.
[Generator]
1. Disconnect negative cable at battery. Remove
distributor, and then ignitor and generator.
2. Remove dust cover from ignitor.
3. Disconnect red and white wires from ignitor.
1. Dust cover2. lgnitor
3. White wire
4. Red wire5. Generator
Fig. 8-13
4. Connect ohmmeter to red and white wires,
and measure generator resistance.
Generator resistance should be within 130 -
190 ohms. If resistance is not within specifi-
cation, replace the generator.
8-6

I
Generator (Pickup
coil) resistance130 - 190 ohmsI
1
1. White wire2. Red wire
Fig. 8-14
5. After checking, connect red and white wires
to ignitor as shown in Figure 8-15, and then
install dust cover.
NOTE:
NEVER connect red and white wires reversely.
Reverse connection may cause damage to
generator and ignitor.
1. White wire2. Red wire
3. lgnitor
4. Generator
Fig. 8-15
6. After generator has been assembled on
distributor, make sure to adjust air gap and
install ignitor.
7. Install distributor referring to page 8-11.
[ Ignitorl
1. Disconnect negative cable at battery. Remove
distributor, and then ignitor and generator.
2. Remove dust cover from ignitor.
3. Disconnect red and white wires from ignitor.
4. Connect an ohmmeter, a bulb and 12 voltage
battery to ignitor as shown in Figure 8-16.
Set ohmmeter at 1 ohm to 10 ohm range.
Then bring ohmmeter negative @ prod to
touch red wire terminal of ignitor, and
positive @ prod to touch white wire terminal.
If bulb is illuminated, it indicates that ignitor
is satisfactory. If not, replace ignitor.
NOTE:
l Never connect battery positive and negative
wires reversely. Reverse connection may cause
damage to ignitior.
l Under no circumstances should ohmmeter be
connected reversely.
l Be sure to perform this ohmmeter check
within a short time (two to three seconds).
1
1. lgnitor5.Negative prod9.Black/Whitewire
2. Bulb6.Red wire terminal10.Brown wire
3. Ohmmeter7.Positive prod11.Earth
4. Battery (12V)8.White wire terminal
Fig. 8-16
c---------~
Bulb
T_-.
ITester (+) PIUSL------------
Fig. 8-17
8-7

5. After checking, connect red and white wires
of generator to ignitor and install dust cover
on ignitor.
Refer to Fig. 8-15 for proper connection of
red and white wires.
6. After the generator and ignitor have been
assembled on the distributor, make sure to
adjust the air gap.
7. Install distributor referring to page 8-11.
[Distributor driven gear]
Inspect gear teeth for wear, and see if the
backlash is normal or not. Excessive backlash
can be told by turning the shaft back and forth,
with its driven gear in mesh with driving gear.
Maladjusted ignition timing is often due to
excessive tooth wear in this gearing and, in such
a case, can be corrected by replacing driven gear.
Fig. 8-18
To replace driven gear, grind off both caulk-
ed ends of driven gear set pin with grinder and
drive it off. After fitting new gear, make sure to
use a new pin and caulk its both ends.
Fig. 8- 191. Driven gear set pin
8-8

Ignition Timing
Ignition timing10” BTDC at
800 * 50 r/min
1 Ignition orderIl-3-4-2I
When checking and adjusting ignition timing,
be sure to use timing light (09900-27301 or
09900-27311).
NOTE:
Prior to check and adjustment of ignition timing,
make sure that head lights, heater fan, rear
defogger (if equipped), and air conditioner (if
equipped) are “OFF”. If any one of these
systems is “ON”,idle up system operates and
engine idle speed will be out of the specification.
[Checking]
1. Remove rubber plug from timing check
window on the transmission case.
2. Start engine and warm it up to normal operat-
ing temperature.
3. After warming up, check to be sure that idle
speed is within specification. If idle speed is
out of specification, adjust it by turning
idle speed adjusting screw of carburetor.
4. Connect timing light to high tension cord of
No. 1 cylinder.
5. With engine running at specified idle speed,
direct the timing light to timing check win-
dow. If 10” BTDC timing mark@on flywheel
appears aligned to timing match mark @ ,
ignition is properly timed.
Fig. 8-20
[Adjusting]
lf ignition timing is out of specification, adjust
it.
Loosen distributor flange bolt and turn distri-
butor housing in place to advance or retard
timing.
Turning housing counterclockwise advances
timing, and vice versa. After adjustment, tighten
flange bolt and recheck timing.
Fig. 8-21
1. Distributor flange bolt
2. Timing is retarded
3. Timing is advanced
Be sure to re-install check window rubber plug
after making above check and adjustment.
WARNING:
When engine is warmed up, exhaust mani-
fold cover and other parts are hot as well.
Be careful not to touch them when remov-
ing and reinstalling rubber plug.
[Checking centrifugal advancer]
After removing distributor cap, turn rotor
clockwise by finger and release it
Check that rotor returns smoothly counterclock-
wise by spring force.
If defective, replace distributor.
Fig. 8-22
8-9

[Checking vacuum advancer]
Remove distributor cap.
Disconnect vacuum hose from vacuum hose 3
way joint, and connect vacuum pump gauge
(0991747910) to its hose. Apply vacuum (ab-
out 400 mmHg). And then with pump stopped,
check to ensure that vacuum pump gauge
indicator remains at the same level, and release
it. Check that generator base plate with gene-
rator moves smoothly. If plate does not move
smoothly, replace defective parts.
Fig. 8-24
1. Distributor drive gear
2. Camshaft3. Cylinder head
Fig. 8-23
@I Vacuum pump gauge (a991 7-47910)
1. Generator base plate
2. Vacuum controller
Distributor Drive Gear
NOTE:
When removing distributor gear case from cylin-
der head, engine oil in cylinder head may come
out. So place waste or receiver under gear case
when removing.
Inspect drive gear for wear.
Worn gear is likely to disturb ignition timing
and therefore must be replaced.
Replacing worn-down drive gear is not enough.
Inspect driven gear (a part of the distributor
assembly), too, and replace it if badly worn
down.
[Important reminders for removal and installa-
tion]
Before removing drive gear from camshaft,
scribe a match mark on this shaft to root
center line of drive gear as shown in Fig.
B-25 and, when mounting replacement drive
gear, refer to this mark.
When pressing replacement drive gear onto
camshaft, be sure to position gear angularly
as shown in Fig. B-25. (align mark on Cam-
shaft scribed in removal with root center of
drive gear)
NOTE:
There is no need to discriminate between two
end faces of drive gear.
Distributor side view
1. Drive gear
2. Camshaft
3. Center line of
45mmhole
4. Center line ofroot5. @5mm hole(Provided on pulleyside of camshaft)
6. Scribed matchmark
7. 5O
Fig. 8-25
l About 30 cc(1.01/l .05 US/Imp 02) of
engine oil must be fed into distributor gear
case after servicing this case, that is, removing
and putting it back. Be sure to add this much
oil before starting engine for the first time
after servicing.
8-11