1987 SUZUKI GRAND VITARA Service Repair Manual

5-3. MAINTENANCE SERVICE
GENERAL
If the emission control hoses were disconnected
and any system component was removed for
service,be sure to reinstall the component
properly and route and connect hoses correctly
after service. Refer to Fig. 5-l-l for hose con-
nection.
PCV SYSTEM
Checking PCV System
NOTE:
If the engine is idling rough, this may be caused
by a stuck PCV valve, plugged hoses or vacuum
leakage of PCV line, therefore, never adjust the
carburetor idle without first checking the PCV
valve and hoses.
[ PCV hoses]
Check hoses for connection, leakage, clog, and
deterioration. Replace as necessary.
[ PCV valve]
Disconnect PCV hoses at three way joint.
Run engine at idle.
Place your thumb over the end of disconnect-
ed PCV hose to check for vacuum. If there is
no vacuum, check for clogged hose or valve.
Replace as necessary.
4) After checking vacuum, stop engine and check
PCV valve for sticking.
With engine stopped, ‘remove PCV hose and
connect a new hose to PCV valve.
Blow air into new hose and check that air
flows with difficulty from cylinder head side
to intake manifold side. If air flows without
difficulty, the valve is stuck in “Open”
position. Replace PCV valve. Before installing
new PCV valve to intake manifold, wind
sealing tape on thread of the valve.
WARNING:
Do not suck air through PCV valve. The
petroleum substances inside the valve and
fuel vapor inside intake manifold are
harmful.
1. PCV valve
2. New PCV hose3. Blow air
Fig. 5-3-2 Checking PCV valve for sticking
5) Connect PCV hose securely.
1. PCV valve
2. PCV hose
3. Three way joint
Fig. 5-3- 1 Checking vacuum
5-18

TCAC SYSTEM
Checking TCAC System
1) Check vacuum hose for connection, deterio-
ration or damage. Replace as necessary.
4 3
3) Check that when engine is started (and run at
idle speed) under the condition that air
cleaner is cool, valve on warm air side becomes
fully open and one on fresh air inhaling side
is completely closed.
4) If nothing was found faulty in the above step,
connect warm air hose.
1. Air control actuator
2. Therm0 sensor3. Check valve
4. Orange side
Fig, 5-3-3TCA C sys tern
2) With engine at a stop, make sure that the
valve indicated in figure is completely closed
(closing warm air side). This check should be
carried out by putting finger into duct after
removing warm air hose from it.
Fig. 5-3-4Checking TCA C sys tern
If found defective in above step 2) or 3),
inspect following parts according to each
procedure.
[Air control actuator]
1) Disconnect vacuum hose from therm0 sensor.
2) Make sure that damper opens fully when
more than 20 cmHg (7.87 in.Hg) vacuum is
applied to ACA.
Also, make sure that damper is held at the
same position when a constant vacuum is
applied to it.
If damper doesn’t open or close smoothly, or
it isn’t held at the same position, replace ACA.
Fig. 5-3-5 Checking A CA
3
4
1. Air cleaner
2. ACA3. Damper valve
4. Warm air5. Fresh air
[Thermo sensor]
1) Remove air cleaner case cap.
2) Disconnect two vacuum hoses from therm0
sensor.
I) Measure the temperature around therm0
sensor.
.) Close a nozzle with finger and then blow air
into nozzle. If measured temperature is above
40°C (104” F), air should come out of therm0
sensor valve (valve is open) as shown in Fig.
5-3-6.
If the temperature is below 25°C (77”F), air
should not come out (valve is closed).
Replace defective parts.5-19

NOTE:
l To check therm0 sensor for operation at
higher than 40°C (104” F) temperature when
therm0 sensor is lower than 25°C (77” F),
remove therm0 sensor from air cleaner cap
and warm it up with hair drier or photo light
before checking.
l Never touch bimetal or valve in therm0
sensor.
1. Therm0 sensor
2. Nozzle3. Nozzle
4. Air cleaner cap
Fig. 5-3-6 Checking therm0 sensor
5) After checking, reinstall air cleaner case cap,
and connect 2 vacuum hoses to therm0
sensor.
[Check valve]
1) Remove check valve with vacuum hose.
2) Using vacuum pump gauge, check for the
following.
When pump operation is stopped,pump gauge pointer stays constant.
When pump is operated, pointermoves considerably but movesback to zero position as soonas pump operation is stopped.
Fig. 5-3-7 Checking check valve
If found defective, replace.

3) Install check valve with its orange side directed
toward therm0 valve.
EVAPORATIVE EMISSION CONTROL
SYSTEM
Checking vapor storage canister
DO NOT SUCK the nozzles on canister
1) Disconnect negative cable at battery.
2) Disconnect 3 hoses from canister.
3) Remove canister.
air into pipe A strongly, and air should come
out from pipe B.
pass through pipe A, C or D.
6) When air is blown into pipe C, air should
come out from pipe A, B and D.
If operation differs from above description,
canister must be replaced.
1. Vapor to carburetor6. Air flow under
2. Vapor from fuel tankvacuum condition
3. Filter7. Vapor from float
4. Charcoalchamber when ignition
5. Filterswitch is “OFF”
Fig. 5-3-8 Checking canister
7) Install canister and connect hoses and battery
negative cable.
5-20

[Hoses]
Visually inspect hoses and pipe for cracks,
damage, or excessive bends, and hose connec-
tion for tightness.
Fig. 5-3-9
HOT IDLE COMPENSATOR (HIC)
Checking Hot Idle Compensator
1) Remove air intake case with hose.
2) Check temperature around HIC with thermo-
meter.
3) If temperature is below 45°C (113” F), air
should not come out of HIC when air is
blown into hose. If temperature is above
65°C (149” F), air comes out of HIC.
Replace H IC if defective.
4) After checking, install air intake case and
connect hose to intake manifold.
NOTE:
l To check HIC for operation at higher than
65°C (149°F) temperature when HIC (bi-
metal) temperature is lower than 45°C
(113”F), warm it up with hair drier or photo
light before checking.
l Never touch bimetal or valve in HIC.
1
Below 45°C (113’F)Above 65’C (149’F)
Fig.5-i- 10
DECELERATION MIXTURE CONTROL
SYSTEM
Checking
[Hoses]
Inspect each hose for pinholes, cracks or damage.
Also check to ensure that each joint is securely
connected. Any part found defective must be
corrected or replaced.
.
Fig. 5-3- 11
[Mixture control valve (MCV)]
1) Warm up the engine to normal operating
temperature.
2) Disconnect hose @ and reconnect it. At this
time, check that air is drawn into MCV.
NOTE:
At this time, the engine will idle rough or die,
but this is normal.
A piece of paper
If the above checks show anything wrong,
replace it.
5-21

[Jet1
1) Remove jet.
2) When blowing air into pipe 0, air should
come out of pipe 0.
Replace clogged jet.
3) Install jet with its gray side directed toward
MCV.
1. Pipe (Gray side)2.Pipe
33.Jet
Fig.53-134.Blowair
FEED BACK SYSTEM
Whether feed back system including oxygen sensor and ECM (Electronic Control Module) is in good
condition or not, can be judged by checking for operation of “CHECK ENGINE” light in instrument clus-
ter..
[U.S.A. specification vehicle]
As previously outlined,“CHECK ENGINE” light automatically flashes at 50,000 miles, 80,000 miles and
100,000 miles indicated on odometer when running warmed up engine. And this automatical flashing at
above mileages proves that system is in good condition.
Should any of following malcondition occur, the system check can be .performed according to “System
check flow chart”,even when mileage indicated by odometer is not any of 50,000 miles, 80,000 miles
and 100,000 miles.
[Canadian specification vehicle]
Should any of following malconditions occur, the system check can be performed according to “System
check flow chart”.
l Fuel consumption increases excssively even in normal driving.
l Engine tends to stall.
l Engine is hard to start.
System check
STARTI
Cancel or check
switch ON
“CHECK EN-
Yes
Inspection, repair of
lamp and wiring1
Warm up engine and
operate at no load
I
“CHECK EN-GINE”light turnonand off (flashes)I
NoSystem inspection OK
and repair
Cancel or check
Fig. 5-3-14System check flow chart
5-22

Checking feed back system
1) Operate (turn ON) cancel switch or check
l Defective oxygen sensor
l Defective mixture control solenoid valve
switch located at the place shown in belowl Defective carburetor or maladjusted idle
figure.mixture
-
1. Cancel switch (U.S.A.)Check switch (Canada)
2. Instrument panel
w
$
1
3. Steering columnholder bracket
4. Steering wheel
Fig. 5-3- 15 Cancel switch or check switch
2) Turn ignition switch
engine.
At this time, “CHECK
ON without running
ENGINE” light should
light (should not flash).
If it does not light, check electric circuit of
the light, namely light for blow off and lead
wire for disconnection.
Fig. 5-3- 16 “CHECK ENGINE” light
3) After lighting of the light is confirmed, start
engine and warm it up to normal operating
temperature.
4) When engine is warmed up, run engine at
1,500- 2,000 rpm. In this state, make sure
that “CHECK ENGINE”lightflashes. Flashing
of light proves that system is in good condition.
If light does not flash, it can be caused by
one of the following. Check them and replace
or adjust as necessary.
l Defective thermal switch
l Disconnected or loosely connected electric
lead wires of emission control systems
l Defective ECM
l Defective micro switches (idle and wot)
5)After making sure that “CHECK ENGINE”
light flashes, turn cancel switch OFF. Light
should go off.
6) Stop engine.
Checking idle and wide open micro switches
Check idle and wide open micro switches
according to the following procedures.
1. Warm up engine to normal operating tempe-
rature and stop engine.
2. For this check, use check terminal coming
from the lower right of instrument panel as
shown.
Connect negative prod of ohmmeter to check
terminal and positive prod to body.
Iht green wire
eck terminal
3. Instrument panel
4. Glove box lid
3. Turn ignition switch to “ON” position.
4. Observe ohmmeter indicator reaction to make
sure for the following movement for each
throttle valve position.
5-23

THROTTLE VALVEINDICATOR
POSITIONMOVEMENT
Idle positionSwing
l/2 openStay after deflection
Full openSwing
NOTE:
If indicator doesn’t deflect at all, reverse above
connection, that is, negative prod to body and
positive one to check terminal, and carry out the
same check.
Fig. 53- 18
1. Check terminal
If check results are not satisfactory, check idle
and wide open micro switches as follows or their
circuits for continuity referring to item “check-
ing sensors and their lead wires ” (p. 5-32).
[Idle micro switch]
1) Remove carburetor following normal service
procedures.
2) Turn fast idle cam counterclockwise and
insert a suitable pin available then into
holes in cam and bracket to lock the cam.
1, Fast idle cam3. Pin
2. Bracket4. Plier
3) Connect ohmmeter to terminals of idle micro
switch. Check for continuity between termi-
nals. When throttle valve is at idle position,
ohmmeter should indicated “zero” ohm.
4) Open throttle valve by l/4 to l/2, and ohm-
meter indicator should indicate infinity.
If check results in steps 3) and 4) are not
satisfactory, replace idle micro switch with a
new one.
1.idle micro switch
2. Green coupler (4P)
3. idle micro switch’s terminals(Green/White and Black wires)
Fig. 5-3-20 Connecting ohmmeter to idle micro
switch
5) Open throttle valve slowly till throttle valve-
to-carburetor bore clearance becomes 0.36 -
0.62 mm (0.014 - 0.024 in) and check that
ohmmeter indicator moves from “zero” ohm
to infinity then.
If the above indicator movement does not
occur within specified range, make adjust-
ment by bending lever shown in below figure.
Bend lever down when clearance is below
specification and up when over specification.
n
1. Primary throttle valve2. Clearance
Fig. 5-3-21 Clearance between throttle valve
and carburetor bore
Fig. 5-3- 19
5-24 4

Fig. 5-3-22 Lever
1. Lever
.
[Wide open micro switch]
1) Connect ohmmeter to wide open micro
switch as indicated in below figure.
At this time, ohmmeter indicator should
indicate “zero” ohm.
2) When throttle valve is fully opened, ohmmeter
should indicate infinity.
If any defect, replace.
1. Wide open micro switch
2. Yellow coupler
3. Green coupler (4P)4. Wide open micro switch’sterminals(Green and Black/Yellow wires)
Fig. 5-3-23 Checking wide open micro switch
3) Open throttle valve gradually until the ohm-
meter indicates infinity. Then, using a vernier,
measure the clearance between throttle valve
and carburetor bore as shown in below figure.
The clearance should be within 6.0 - 7.2 mm
(0.24- 0.28 in). If the clearance is out of
specified range, make adjustment by bending
the lever in below figure.
1. Primary throttle valve2. Clearance
Fig. 5-3-24 Clearance between throttle valve
and carburetor bore
1. Wide open micro switch lever
Fig. 5-3-25 Wide open micro switch lever
Upon completion of checks, install carburetor
following normal service procedures.
Checking mixture control solenoid valve
1) Check to make sure that ignition switch is at
“OFF” position.
2) Disconnect couplers from ECM, TWSVs and
vsv.
3) Disconnect mixture control solenoid valve
lead wires at the coupler (5P).
Fig. 5-3-26
1. Green coupler (BP)
5-25