Diagnosing Starting Problems on the Fiat-Hitachi FH130-6

[MikePhua]

The FH130-6 and Its Place in Excavator History
The Fiat-Hitachi FH130-6 excavator emerged during the late 1990s as part of a joint venture between Fiat and Hitachi, combining Italian mechanical engineering with Japanese hydraulic precision. This partnership produced a range of mid-sized excavators that were widely adopted across Europe and parts of Asia. The FH130-6, with its 13-ton operating weight and robust Isuzu diesel engine, was designed for versatility in urban construction, roadwork, and utility trenching.
Fiat-Hitachi machines were known for their straightforward design and ease of service, which made them popular among independent contractors and municipal fleets. By the early 2000s, thousands of FH-series units had been sold, and many remain in operation today, particularly in regions where parts support and mechanical familiarity persist.
Common Starting Issues and Initial Checks
Starting problems on older excavators like the FH130-6 often stem from a combination of fuel delivery issues, electrical faults, and wear in key components. In this case, the machine exhibited intermittent behavior: sometimes starting immediately, other times cranking without firing until the fuel system was bled again.
Initial steps taken included:

• Replacing fuel filters
  
• Installing a new lift pump
  
• Checking injectors for flow and spray pattern
  

These are standard procedures when diagnosing diesel engine starting issues. However, the fact that the machine would start randomly after bleeding the system suggests an underlying issue with fuel delivery consistency or air intrusion.
Understanding Diesel Fuel Systems
Diesel engines rely on high-pressure fuel delivery and precise timing to ignite the air-fuel mixture via compression. The FH130-6 uses a mechanical injection system, which includes:

• Lift Pump: Transfers fuel from the tank to the injection pump. A weak or failing lift pump can cause hard starts.
  
• Injection Pump: Pressurizes fuel and meters it to the injectors. Timing and internal wear affect performance.
  
• Injectors: Spray atomized fuel into the combustion chamber. Dirty or worn injectors lead to poor combustion.
  
• Fuel Lines and Fittings: Any leaks or loose connections can introduce air, causing vapor lock or inconsistent pressure.
  

Air in the system is a common culprit in older machines. Even a pinhole leak in a return line or a cracked banjo fitting can allow air to enter, especially after shutdown when vacuum pressure changes.
Bleeding the System and Temporary Relief
Bleeding the fuel system involves manually purging air from the lines and components. On the FH130-6, this typically means:

• Loosening injector line nuts
  
• Cranking the engine until fuel spurts from each line
  
• Retightening the fittings in sequence
  

While this temporarily restores function, repeated need for bleeding indicates a persistent leak or suction-side fault. One operator described the machine “just going” after bleeding, which suggests that fuel delivery resumes once pressure is restored—but fails again due to air re-entry.
Electrical Factors and Cold Start Behavior
Though the focus was on fuel, electrical issues can also mimic fuel-related symptoms. Key areas to inspect include:

• Battery Voltage: A weak battery may crank the engine but fail to energize the fuel solenoid.
  
• Starter Motor: Worn brushes or solenoid contacts can cause inconsistent cranking speed.
  
• Fuel Shutoff Solenoid: If this fails to open fully, fuel flow is restricted. Listen for a click when the key is turned.
  

In colder climates, glow plugs or intake heaters may be present. If these fail, cold starts become difficult, especially with older diesel formulations that gel below freezing.
Field Anecdote and Practical Advice
A contractor in Scotland once shared his experience with a similar FH-series excavator. After months of chasing intermittent starts, he discovered a hairline crack in the plastic fuel pickup tube inside the tank. It would draw air when the tank was below half full, but run fine when topped off. His solution? Replace the pickup tube with a copper line and install a clear inline filter to monitor flow.
This kind of field ingenuity is common among operators who rely on aging equipment. Visual aids like clear filters, fuel pressure gauges, and even temporary gravity-fed setups can help isolate faults.
Preventive Measures and Long-Term Fixes
To resolve starting issues permanently, consider the following:

• Replace all rubber fuel lines with reinforced hose rated for diesel.
  
• Install spring clamps or double hose clamps at all junctions.
  
• Pressure test the fuel system using a hand pump and gauge.
  
• Upgrade to an electric lift pump with consistent flow and priming capability.
  
• Clean or replace the fuel tank if sediment or microbial growth is present.
  

Additionally, consider installing a fuel water separator with a drain valve. Water in diesel can cause injector damage and corrosion in the pump.
Conclusion
Starting issues on the Fiat-Hitachi FH130-6 are often a symptom of deeper fuel system inconsistencies. While bleeding restores function temporarily, the root cause must be addressed to ensure reliability. By combining mechanical inspection with field-tested solutions, operators can keep these legacy machines running strong. The FH130-6 remains a testament to durable design, and with proper care, it continues to serve in jobsites where newer machines might falter.