When the engine is running, the air intake valve is lifting up.
If the valve does not operate properly, check the air intake solenoid valve hoses for leak.
If there are no leaks, check the air intake solenoid valve.

Air Intake Solenoid Valve Unit TestIntake Air Pressure Sensor #2 Output Voltage Inspection
Measure the output voltage at the intake air pressure sensor
#2 in the same way as input voltage inspection, note
the following.
Disconnect the intake air pressure sensor #2 connector
and connect the measuring adapter [A] between these
connectors.
[B] Main Harness
[C] Intake Air Pressu ...
Transmission Shaft Disassembly
Remove the transmission shafts (see Transmission Shaft
Removal).
Remove the circlips, and then disassemble the transmission
shafts.
Special Tool - Outside Circlip Pliers: 57001-144
The 5th gear [A] on the output shaft has three steel balls
assembled into it for the positive neutral fin ...
Connecting Rod Bend Inspection
Remove the connecting rod big end bearing inserts, and
reinstall the connecting rod big end cap.
Select an arbor [A] of the same diameter as the connecting
rod big end, and insert the arbor through the connecting
rod big end.
Select an arbor of the same diameter as the piston pin
and ...