Hitachi ZW 120-6 Operator's Manual page 350

Engine does not Start.
Symptom
The starter does not turn.
Although the starter turns, the engine
does not start.
Engine speed does not increase.
Although the engine cranks, running
speed is low and easy to stall.
Control Lever
Symptom
Hard to move
Does not move smoothly.
Does not return to neutral.
The lever is tilted in the neutral position
due to increase in play.
The lever is not held with magnetic
detent.
TROUBLESHOOTING
Cause
Reduced battery voltage
High resistance in the starter circuit
Faulty key switch
Damaged wire harness
Faulty battery relay
Blown slow blow fuse link
The forward/reverse selector lever is in either
the forward or reverse position.
Faulty starter
Battery disconnect switch is turned OFF.
Use of poor quality fuel, insufficient fuel, lack
of fuel
Faulty glow plug
Air mixed in the fuel supply line
Faulty injection pump or nozzle
Reduced compression pressure
The accelerator pedal function is abnormal.
DEF/AdBlue® tank is empty.
Deteriorated engine oil
Contaminated injection nozzle
Clogged fuel filter
Clogged feed pump strainer
Air mixed in the fuel supply line
Cause
Rusted joint
Worn pusher
Worn pusher
Faulty pilot valve
Faulty pilot valve
Worn joint
Faulty pilot valve
Faulty magnetic solenoid
Faulty sensor
11-2
Solution
Charge the batteries. Replace.
* Clean and/or retighten the
battery terminals and starter
terminals.
* Replace
* Repair, Replace
* Replace
* Replace
Return to neutral.
* Repair, Replace
Turn the switch ON.
Change fuel. Refill tank with
good quality fuel.
* Replace glow plug.
Bleed air
* Repair, Replace
* Adjust
Replace the accelerator pedal
or parts.
Supply DEF/AdBlue®
Change engine oil.
* Replace
Replace
Clean
Bleed air
* Consult your nearest authorized dealer.
Solution
* Lubricate, Repair
* Replace
* Repair, Replace
* Replace
* Replace
* Repair, Replace
* Replace
* Replace
* Replace
* Consult your nearest authorized dealer.