During routine construction operations, if
an excavator suddenly stalls while working, it not only disrupts construction
progress but may also cause potential damage to the equipment. To help users
quickly identify the cause of the malfunction and take effective measures, we
have systematically compiled common causes and troubleshooting methods for
excavator stalling. This information is provided for reference.
I. Analysis of Common Failure Causes
Fuel System Issues
Abnormalities in fuel combustion may cause
unstable engine operation or spontaneous shutdown. Simultaneously, fuel line
leaks (oil or air), or injector pump malfunctions can disrupt fuel supply
continuity, leading to stalling.
Poor Fuel Delivery or Insufficient Lubrication
If symptoms like gradually decreasing
engine speed or black smoke from the exhaust pipe occur before stalling, this
typically indicates poor fuel delivery or inadequate engine lubrication. Severe
cases may lead to mechanical failures such as crankshaft seizure or bearing
burnout.
Substandard Diesel Fuel Quality
Using unclean diesel fuel can easily clog
the fuel filter or impair injector function, causing the engine to suddenly
stall during operation. In such cases, prioritize replacing the diesel filter
and inspect or calibrate the injectors.
High-pressure fuel pump or injector
malfunction
If the equipment stalls automatically after
warming up and cannot be restarted within a short time, it may indicate
abnormal operation of the high-pressure fuel pump or injectors. Cooling the
diesel pump can provide an initial diagnosis: if the engine starts immediately
after cooling, it confirms a pump or injector fault.
Excessive Intake or Fuel Supply Resistance
Increased intake resistance or fuel supply
blockage can reduce combustion efficiency, leading to stalling.
Abnormal Hydraulic System Load
When hydraulic pump pressure becomes
excessively high, causing an imbalance in power distribution between the engine
and hydraulic system, “choke-out stalling” may occur.
Electrical Control System Malfunction
Receiving erroneous signals may trigger the
automatic stall protection mechanism.
II. Troubleshooting and Recommendations
When an excavator suddenly stalls during
operation, especially in a “choke-out” scenario, follow these sequential steps:
Inspect the Fuel Supply System
First, verify unobstructed fuel flow,
checking for blockages, fuel leaks, or air leaks. Clean or replace the fuel
filter element; replace all filter elements if necessary. Disassemble and
inspect the diesel pump, ensuring the fuel nozzle spray length meets the
standard range of approximately 6–7 mm.
Check for Engine Overload or Overheating
Prolonged high-load operation may cause
engine overheating, triggering self-protection mechanisms. Inspect the cooling
system and verify appropriate workload levels.
Focus on fuel line sealing integrity
Thoroughly inspect fuel lines for air or
oil leaks. Check if pipe joint seals are aged or damaged. Verify that filters
are not clogged and that the water separator drain plug is securely tightened.
Assess hydraulic system compatibility
If a hydraulic system issue is suspected,
use professional testing equipment to measure hydraulic pump pressure. Verify
that the engine and hydraulic pump power ratings are matched. Have a qualified
technician perform valve assembly calibration.
III. Service Support Guidelines
Excavator stalling issues are typically
closely related to the fuel system but may also involve the engine, hydraulic
system, or electronic control system. Users are advised to conduct basic
troubleshooting following the steps above. If the problem is straightforward,
it can be resolved independently. If unable to resolve the issue, promptly
contact Baoding Excavator's after-sales service department or your regional
sales manager. Our professional technical team will provide comprehensive and efficient
technical support to ensure stable equipment operation.
Through scientific maintenance and
standardized operation, the frequency of unexpected failures can be effectively
reduced, extending equipment lifespan and ensuring sustained, stable improvements
in construction efficiency.
