Diagnosing a No-Start Condition on the Ingersoll Rand 185 Air Compressor

[MikePhua]

The IR 185 and Its Role in Portable Air Systems
The Ingersoll Rand 185 portable air compressor is a staple in construction, roadwork, and utility maintenance. Designed to deliver 185 CFM at 100 psi, it’s powered by a diesel engine—typically a John Deere or Deutz four-cylinder—coupled to a rotary screw compressor. Its rugged frame, weatherproof enclosure, and simple control panel make it a favorite for mobile operations. However, like any diesel-powered machine, it can suffer from intermittent no-start conditions that require methodical troubleshooting.
Symptoms of a No-Start Condition
When the IR 185 turns over but refuses to start, operators may observe:

• Starter motor engages and cranks the engine normally
  
• No smoke from the exhaust during cranking
  
• Fuel level appears sufficient
  
• Battery voltage is adequate
  
• No fault codes or warning lights on the panel
  
• Glow plug indicator may or may not illuminate
  

These symptoms suggest that the issue lies in fuel delivery, air intake, or ignition timing—not mechanical seizure or electrical failure.
Primary Causes of No-Start in Diesel Compressors
Several root causes are commonly encountered:

• Fuel solenoid failure
  The fuel shutoff solenoid controls diesel flow to the injection pump. If it fails or loses power, fuel cannot reach the cylinders.
  
• Air in the fuel system
  After filter changes or prolonged storage, air pockets can prevent injection. Bleeding the system is essential.
  
• Glow plug malfunction
  In cold weather, failed glow plugs or relays can prevent combustion. Check resistance and voltage at each plug.
  
• Low compression
  Worn rings or valves reduce combustion efficiency. A compression test can confirm this.
  
• Faulty safety switches
  Oil pressure or temperature sensors may prevent starting if they falsely report unsafe conditions.
  
• Starter speed too low
  Diesel engines require high cranking RPM to build compression. Weak batteries or corroded cables can reduce starter speed.
  

A technician in Alberta once diagnosed a no-start IR 185 that had sat idle for six months. After replacing the fuel solenoid and bleeding the lines, the machine fired up immediately.
Step-by-Step Diagnostic Strategy
To isolate the fault:

• Check battery voltage under load. Minimum 12.4V during cranking is ideal.
  
• Inspect fuel solenoid for audible click and verify voltage at the terminal.
  
• Crack injector lines and observe fuel spray during cranking.
  
• Test glow plug resistance and verify relay function.
  
• Inspect air filter and intake path for obstructions.
  
• Perform compression test if all else fails.
  

If fuel is present but no smoke appears, combustion is not occurring—pointing to glow plug or compression issues.
Preventive Measures and Long-Term Reliability
To reduce future no-start events:

• Replace fuel filters every 250 hours
  
• Bleed fuel system after any service interruption
  
• Test glow plugs annually and replace as needed
  
• Keep batteries fully charged and terminals clean
  
• Store the unit with a full tank and fuel stabilizer
  
• Exercise the compressor monthly to prevent varnish buildup
  

Some operators install manual override switches for the fuel solenoid to bypass faulty sensors during field emergencies.
A Story from the Field
In 2022, a road crew in Montana faced a no-start IR 185 during a bridge repair. The compressor had been stored in a shed all winter. Despite cranking well, it refused to fire. A mechanic discovered the fuel solenoid had seized internally. After replacing it and bleeding the lines, the unit started and ran flawlessly. The crew later added a pre-start checklist to their morning routine, including solenoid testing and glow plug verification.
Conclusion
A no-start condition on the IR 185 compressor is often solvable with systematic diagnostics. Whether it’s fuel delivery, glow plug failure, or sensor interference, the key is to isolate each system and verify function. In portable air systems, reliability begins with combustion. When the engine roars and the air flows, the jobsite moves forward with power and precision.