Daihatsu F300 Service Manual page 1360

EMISSION CONTROL SYSTEM
• THROTTLE POSITIONER (TP) SYSTEM
•
•
•
This system prevents the throttle valve from suddenly closing, thus reducing the CO and HC emissions.
Throttte valve closing
Throttle valve opening
..
..
Conditions
'
TP diaphragm
Idling Pushed in by return force of throttle valve
Normal driving Pushed out by diaphragm spring
Deceleration
• Pushed in by return force of throttle valve
Throttle valve
Idle speed position
Opened position
Diaphragm
spnng
Air valve
WFEQO.EC061
Slightly opens and then slowly closes to the idle
position.
• At this point, the function of the air valve provided inside the throttle positioner diaphragm prevents the throttle valve from being
closed suddenly.
INSPECTION OF THROTTLE POSITIONER (TP)
SYSTEM
1. Warm up the engine.
2. Check the idle speed. Adjust the speed, if necessary.
3. Check of TP setting speed
( 1) Raise the engine speed to approximately 3000 rpm.
(2) Close the throttle valve slowly_
(3) Observe the engine speed at a time when the dashpot
lever comes in contact with the throttle lever.
Engine Speed:
General Spc: 1800
±
1 00 rpm
US Spc: 1600
±
100
rpm
If the engine speed does not conform
to
the specifica-
tion, perform adjustment by turning the TP adjusting
screw .
EC-21