Suzuki GA413, Service Manual

Page: 468 / 1246

NOTE:
IAC duty can be checked roughly by using voltmeter. IAC
duty to voltage relation is as follows.
“OFF DUTY METER” is such duty meter that indicates
approx. 100% when terminal voltage is approx. “0V”.
“V
B
” represents battery voltage while engine of vehicle be-
ing checked is running.
8) If idle speed and/or duty is out of specifications, check idle air
control system. Refer to “B-4 Idle Air Control System Check” in
this section.
IDLE MIXTURE INSPECTION/ADJUSTMENT
(VEHICLE WITHOUT HEATED OXYGEN SENSOR)
All vehicles not equipped with heated oxygen sensor are shipped
with their CO% factory adjusted as follows.
Idle mixture adjustment should never be changed from the original
factory setting. However, if during diagnosis, check indicates idle
mixture to be cause of a driver performance complaint or emission
failure, idle mixture can be adjusted using the following proce-
dures.
NOTE:
For this inspection and adjustment, exhaust gas tester (CO
meter) and engine tachometer are necessary.
1) Check idle speed according to “Idle Speed/Idle Air Control Duty
Inspection” in this section.
2) Using exhaust gas tester, check that idle mixture CO% is within
above specification. If it is out of specification, adjust it to specifi-
cation by turning resistor knob.
3) If idle mixture has been adjusted, confirm that idle speed and
IAC duty are within specifications.
6E-58 ENGINE AND EMISSION CONTROL SYSTEM
ON DUTY
METER INDICATION
(%)
OFF DUTY
METER INDICATION
(%)
VOLTMETER
INDICATION
(V)
0
50
100
100
50
0
0
0.5 x V
B
V
B
Engine idle mixture
(CO %)
0.8 – 1.3 % at specified idle speed