1987 SUZUKI GRAND VITARA Service Repair Manual

Ambient temperatureClearance
Fig. 4-l-47
Choke Adjustment
Perform following check and adjustments with
air intake case removed when engine is cold.
[Choke valve]
1) Check choke valve for smooth movement by
pushing it with a finger.
Fig. 4-l-48 Choke valve
2) Make sure that choke valve is closed almost
completely when ambient temperature is
below 25°C (77” F) and engine is cold.
3) Check to ensure that choke valve to carbure-
tor bore clearance is within following specifi-
cations when engine is cool.
I.6 mmC&n*?.:.. \
NOTE:
As ambient temperature or engine coolant
temperature rises high, clearance increases.
1. Choke valve2. Thickness gauge
Fig. 4- 149 Choke valve to carbure tar bore
clearance
4) If clearance is found excessively large or
small in the above check, check strangler
spring, choke piston and each link in choke
system for smooth operation. Lubricate
choke valve shaft and each link with spray
lubricant if necessary.
Fig. 4-l-50
4-22

5) If clearance is still out of specification even
after lubrication in step 4), remove carburetor
from intake manifold and remove idle-up
actuator from carburetor.
Then, turn fast idle cam counterclockwise and
insert a pin available into holes in cam and
bracket to lock the cam.
In this state, bend choke lever shown in below
figure up or down, with plier. Bending up
causes choke valve to close, and down to
open.
1. Fast idle cam 3. Pin2. Bracket4. Choke lever
Fig. 4- l-51 Choke lever
6) After installing air intake case, start engine
again and warm it up fully.
7)Stop the engine when it is warmed up and
remove air intake case again, and then check
to ensure that choke valve is fully open.
Fig. 4- l-52
[Choke piston]
Check choke piston as follows.
1) Disconnect choke piston hose at throttle
chamber.
2) With choke valve pushed down to its closing
side lightly by finger, apply vacuum,to choke
piston hose with vacuum pump gauge, and
check to ensure that choke valve to carbure-
tor bore clearance is within the specification.
Choke valve to carbu-1.1 - 1.3 mm
retor bore clearance(0.04 - 0.05 in.)
6
2
4
3/
1. Choke piston hose
2.Chokepiston
3. Vacuum (Apply -30 w-50 cm Hg vacuum)4.Chokevalve
5. Push here lightly
6. Choke valve to carburetor bore clearance
Fig. 4- l-53 Checking choke piston
3) With vacuum appliedas in step 2), move choke
piston rod with small screw driver as shown
and check to ensure that choke valve to car-
buretor bore clearance is within following
specification.
Choke valve to carbu-3.2 - 3.7 mm
retor bore clearance(0.13 - 0.14 in.)
If choke valve doesn’t open fully, defect lies in
wax-element or its link system.
Repair or replace defective parts(s).
4-23

1.Vacuum (Apply-30w-50cmHgvacuum)
2. Choke piston rod3.Screw driver
4. Choke valve to carburetor bore clearance
Fig. 4- l-54 Moving choke piston rod
Fast Idle Adjustment
NOTE:
Fast idle check and adjustment should be per-
formed after making sure of the following.
l Ambient temperature is between 22°C and
28°C (71°F and 82°F).
*Idle up system (idle up speed) is normal.
Check and adjustment procedure is as follows.
1) Leave car at a place where ambient tempe-
rature is between 22°C and 28°C (71°F and
82”F), for over 4 hours.
NOTE:
When carburetor is removed, leave carburetor at
the place mentioned above for an hour and
check as follows.
2) After leaving, make sure that the mark on
cam and the center of cam follower are in
alignment as shown in below figure.
Fast idle cam
Mark on cam
Cam follower
3) Disconnect vacuum hose from TWSV and
connect special tool (vacuum pump gauge) to
its hose.
,
1.2.
3.4.
5.
6.7.
8.
Twsv
Vacuum hose
Idle up actuatorClearanceActuator rodIdle up adjusting screwFast idle adjusting screw
Special tool (Vacuum pump gauge)
With applying about 40 cmHg vacuum to
actuator.
4) Check clearance between actuator rod and
idle up adjusting screw.
Clearance “4”
for fast idle
2.5 - 3.0 mm
(O.lO- 0.12 in.)
If clearance is out of specification, adjust it
to specification with tast idle adjusting screw-
Unloader Adjustment
Perform this check and adjustment when engine
is cool.
1) Remove air intake case.
2) Make sure that choke valve is fully closed.
3) Fully open throttle valve and check choke
valve to carburetor bore clearance to ensure it
is within following specification.
Fig. 4- l-55 Mark on cam and cam follower
4-24

4) If clearance is out of specification, adjust by
bending the unloader arm indicated in belowfigure.
‘
Choke valve to carbu-2.5 - 3.2 mm
retor bore clearance(0.10 - 0.12 in.)
Checking Secondary System
1) Remove air intake case.
2) Disconnect hose @ from 3 way joint, and
connect vacuum pump gauge.
3) Open primary throttly valve fully.
4) Check if secondary throttle valve opens smoothly and is held there when vacuum
(10 cmHg) is applied to actuator.
5) Disconnect hose @ from 3 way joint and
connect vacuum pump gauge to its hose.
Plug hose @ with finger.
. 6) Turn ignition switch to “ON” position and
open primary throttle valve fully. 5 or 6
seconds later, make the .same check as in
above step 4).
1. Unloader arm
2. Fast idle cam
3. Accelerator cable
Fig. 4-
7-57
Unloader lever arm
Checking Acceleration Pump
1) Remove air intake case.
2) Make sure that fuel comes out of pump
discharge nozzle when accelerator pedal is
depressed.
Fig. 4- l-59 2. Hose
4. vsv
If check result in step 4) is not satisfactory,
check VTV, and if that in step 6) is not satis-
factory, check VSV.
If not satisfactory in either step 4) or 6) and both
VTV and VSV are in good condition, replace
actuator.
[VTV (Vacuum Transmitting Valve)]
Remove VTV. Use a vacuum pump gauge for
VTV check. If pointer of vacuum pump gauge reacts as described below in each condition,
VTV is in good condition.
1
I, Pump discharge nozzle
2. Choke,valve
Fig. 4- 1-58 Pump discharge nozzle With vacuum pump gauge set at Brown side of
VTV, when pump is operated, pointer doesn’t
move (remains at zero position).
4- 25

With vacuum pump gauge set at Black side of
VTV, when pump is operated, pointer moves
considerably but moves back to zero position as
soon as pump operation is stopped.
Brown side
(Actuator side) Black side
Fig. 4-l-60
1. VTV
2. Vacuum pump gauge
install VTV. Refer to Fig. 4-l -2 for installation.
[ VSV (Vacuum Switching Valve)]
1) Disconnect VSV vacuum hoses from 3 way
joint and secondary actuator and while
blowing either hose, check that air doesn’t
come out of the other hose.
2) Turn on ignition switch and depress accelera-
tor pedal fully. 5 or 6 seconds later, while
blowing either vacuum hose, check that air
comes out of the other hose.
J5
Fig. 4- l-61
1I
1. vsv4. WOTS
2. Ignition switch5. ECM
3. Battery6. Blow air
If check results in steps 1) and 2)are not satisfac-
tory, either replace VSV or check WOTS and its
circuit referring to SECTION5 “EMISSION
CONTROL SYSTEM”.
Idle Speed Adjustment
NOTE:
Before starting engine, place transmission gear
shift lever in “Neutral”, and set parking brake
and block drive wheels.
Before idle speed check and adjustment, make
sure of the following.
l Lead wires and hoses of engine emission
control systems are connected securely.
l Accelerator cable has some play, that is, it is
not tight.
l All vacuum hoses are connected securely.
l Fuel level should be within round mark at the
center of level gauge.
l Valve lash is checked and adjusted according
to the maintenance schedule.
l Air cleaner has been properly installed and is
in good condition.
l All accessories (wipers, heater, lights, etc) are
out of service.
l Ignition timing is within specification.
l Idle up actuator is not operating when engine
is running at idle speed.
NOTE:
In areas above 4,00Ofeet( 1,220m) elevation
(high altitude), idle up system will be normally
in operation. Do not attempt to adjust the idle
speed.
After above items are all confirmed, adjust idle
speed as follows.
1) Warm up engine to normal operating tempe-
rature.
2) Check to ensure that idle speed is within
750 - 850 r/min (rpm).
3) If idle speed is not within specified range,
adjust by turning idle speed adjusting screw.
If idle speed can not be adjusted to the speci-
fication by turning the adjusting screw, it can
be due to faulty return of throttle valve or
some other reason. Determine cause and
repair, and then adjust idle speed to specifica-
tion.
4-26

1. Idle speed adjusting screw
Fig. 4- l-62 Idle speed adjusting screw
4) After idle speed adjustment, check idle-up for
operation with lights (small light, tail light,
side marker light and license light), heater fan
and rear defogger (if equipped) turned “ON”,
only one at a time. Refer to item “Idle Up
Adjustment”. (p. 4-20).
5) Stop engine and check to ensure that accelera-
tor cable play is within the specification as
previously outlined. If play is out of specifica-
tion, adjust it.
Idle Mixture Inspection and Adjustment
[Inspection]
1) Warm up engine to normal operating tem-
perature.
2) Remove seal rubber of duty check coupler
and connect positive terminal of duty meter
to “Blue/Red” wire and negative terminal to
“Black/Green” wire.
1
1. Duty check
3) Set tachometer.
4) Run engine at 1,500 - 2,000 r/min for 30
seconds and bring it to idle speed.
5) Check duty at specified idle speed. If it is out
of specification, adjust it to specification ac-
cording to following adjustment procedure.
Specified DutyIO-50
at 750 - 850 r/min.
After inspection, install seal rubber to duty
check coupler.
[Idle Mixture Adjustment]
The carburetor has been calibrated at the facto-
ry and. should not normally need adjustment in
the field. For this reason, the mixture adjust-
ment should never be changed from the original
factory setting. However, if during diagnosis, the
check indicates the carburetor to be the cause of
a driver performance complaint or emission
failure, or the carburetor is overhauled or
replaced, the idle mixture can be adjusted using
the following procedure.
After adjustment, mixture adjusting screw pin
must be installed.
Idle mixture adjustment procedure is as follows:
1) Remove carburetor from intake manifold
following normal service procedure to gain
access to mixture adjusting screw pin covering
mixture adjusting screw.
2) Drive out mixture adjusting screw pin using
about 4.5 mm (0.18 in) thick iron rod as
shown below.
1. Mixture adjusting screw pin2. Rod
Fig. 4- l-64 Mixture adjusting screw pin
2. Air intake case
Fig. 4- l-63
4-27

3) Reinstall carburetor following normal service
procedures.
Connect emission control system hoses and
lead wires. Make specified play on accelerator
cable and refill cooling system.
4) Place transaxle gear shift lever in “Neutral”,
set parking brake and block drive wheels.
5) Start engine, and warm it up to normal
operating temperature, stop engine.
6) Be sure to check the following before idle
mixture adjustment.
l Fuel level is within round mark at the
center of level gauge.
l Valve lash is checked and adjusted accord-
ing to the maintenance schedule.
l Air cleaner has been properly installed
and is in good condition.
l All accessories (wipers, heater, lights etc)
are out of service.
l Ignition timing is within specification.
l Choke valve opens fully.
l Idle-up actuator does not operate.
7) Check and adjust idle speed to specification
if necessary.
8) Remove seal rubber of duty check coupler
and connect positive terminal of duty
meter to“Blue/Red” wire and negative
terminal to “Black/Green” wire.
9) Run engine at 1,500 - 2,000 r/min for 30
seconds and bring it to idle speed.
10) With engine running at idle speed, adjust idle
mixture adjusting screw slowly in small incre-
ment allowing time for duty to stabilize after
turning screw to obtain duty of 10 - 50.
If duty is too low, back screw out; if too
high, screw it in. After obtaining duty of
10 - 50, recheck idle speed, and adjust if
necessary.
NOTE:
If adjustment can’t be made because duty meter
indicator does not deflect, check feed back
system according to the checking procedure of
system described in section of Emission Control
System.
11) After adjustment, install seal rubber to duty
check coupler and drive in idle mixture
adjusting screw pin.
4-28

4-2. AIR CLEANER
GENERAL DESCRIPTION
In the air cleaner case, a dry-type air cleaner element is provided for filtering.out dirt and dust from air
being drawn into the engine for combustion.
A damaged element must be replaced with a new one, since it allows dust particles to enter the engine if
used as it is. Such dust particles could cause wear to the engine inner parts and this further results in
decreased output.
Also, the element must be cleaned periodically. Dusty and dirty element causes decrease in output and
increase in fuel consumption. The dusty element even after cleaning should be replaced with a new one.
Fig. 4-2-l
1. Air cleaner case
2. Air cleaner case cap
3. Air cleaner element4. Air cleaner inlet hose
5. Air cleaner outlet hose
6. Warm air hose
7. Carburetor air intake case
8. Check valve
9. Therm0 sensor (valve)10. Air control actuator
MAINTENANCE SERVICES
Air Cleaner Element
[Cleaning]
1) Remove air cleaner outlet hose and case cap.
Fig. 4-2-21. Air cleaner outlet hose2. Air cleaner case cap3. Clamp
4-29