If they appear damaged or deteriorated, replace them.

Balancer Adjustment
Torque LimiterECU Removal
NOTICE
Never drop the ECU especially on a hard surface.
Such a shock to the ECU can damage it.
Remove the upper air cleaner housing (see Air Cleaner
Element Replacement in the Periodic Maintenance chapter).
Lift up the ECU [A] with rubber protector [B] to disconnect
the connectors [C]. ...
Piston Wear Inspection
Measure the outside diameter [A] of each piston 5 mm
(0.20 in.) [B] up from the bottom of the piston at a right
angle to the direction of the piston pin.
If the measurement is under service limit, replace the piston.
Piston Diameter
Standard: 75.959 75.974 mm
(2.9905 2.9911 in.)
...
Throttle Body Assy Disassembly
1. Throttle Body Assy
2. Subthrottle Valve Actuator
3. Idle Speed Control Valve Actuator
4. Main Throttle Sensor
5. Subthrottle Sensor
6. Primary Fuel Injectors
7. Delivery Pipe Assy
NOTICE
Do not remove, disassemble or adjust the main
throttle sensor, subthrottle sensor, subthrottle
v ...