Komatsu 114E-3 Series - S-5 Engine Does Not Rotate Smoothly

SEN00458-01 40 Troubleshooting
12 114E-3 Series
S-5 Engine does not rotate smoothly 1
*1: Code [689/CA689] in E-mode
*2: Code [778/CA778] in E-mode
General causes why engine does not rotate smoothly
q Air in fuel system
q Defective speed sensor (Error at degree that it is not indicated)
Causes
Insufficient fuel in tank Clogged air breather hole of fuel tank cap Leaking or clogged fuel piping, entry of air Clogging of fuel filter Clogged injector, defective spray (dirt in injector) Defective Ne speed sensor, wiring harness Defective Bkup speed sensor, wiring harness
Questions
Confirm recent repair history
Degree of use of machine Operated for long period E
Condition of hunting
Occurs at a certain speed range QQ
Occurs at low idle QQQQQ
Occurs even when speed is raised QQQ
Occurs on slopes w
Replacement of filters has not been carried out according to Operation and Maintenance
Manual
w
When fuel tank is inspected, it is found to be empty w
Check items
Air breather hole of fuel tank cap is clogged w
Rust and water are found when fuel tank is drained Q
Fuel is leaking from fuel piping w
Troubleshooting
Inspect fuel filter, strainer directly q
When a cylinder is cut out for reduced cylinder mode operation, engine speed does not
change
q
Carry out troubleshooting according to “Abnormality in Ne speed sensor (*1)” in E-mode q
Carry out troubleshooting according to “Abnormality in Bkup speed sensor (*2)” in E-mode q
Remedy
Add
Clean
Correct
Replace Replace Replace Replace