Case 1840 Skid Steer Turns But Won’t Start: Troubleshooting Guide

[MikePhua]

The Case 1840 skid steer is a reliable piece of equipment widely used in construction, landscaping, and other industries requiring compact yet powerful machinery. However, like all machinery, it can encounter issues that prevent it from starting. One common issue reported by operators is when the machine turns over but does not start. This problem can be caused by several factors ranging from electrical to fuel system issues.
This article provides a comprehensive troubleshooting guide for diagnosing and resolving the "turns but won't start" issue on a Case 1840 skid steer. By breaking down the potential causes, solutions, and preventive measures, operators can quickly identify the root cause of the problem and take the necessary steps to get the machine running again.
Overview of the Case 1840 Skid Steer
Manufactured by Case Construction, the 1840 skid steer loader is known for its compact size, versatility, and power. With a lift capacity of approximately 1,600 pounds and a range of attachments, the Case 1840 is ideal for tasks such as digging, grading, and material handling. The machine is powered by a diesel engine, which drives both its hydraulic system and the drivetrain.
Despite its robust design, like any mechanical system, the Case 1840 can experience operational issues over time. One of the most frustrating problems is when the engine turns over but fails to start, indicating an underlying issue that needs to be addressed.
Common Causes of "Turns But Won't Start" Issue

1. Fuel System Issues
   One of the most common reasons why a skid steer may turn over but not start is a problem with the fuel system. Diesel engines require proper fuel delivery and air-fuel mixture to start and run correctly. If there is any issue with fuel flow, the engine will not start, even if the starter motor is functioning.
   • Fuel Filter Clogs: A clogged fuel filter can prevent the proper flow of diesel to the engine. Over time, debris and contaminants can build up in the filter, restricting fuel flow. If the fuel filter is clogged, it should be replaced according to the manufacturer’s recommendations.
     
   • Fuel Lines Blockage or Leaks: Check the fuel lines for any signs of blockage or leaks. If the fuel is not reaching the engine, or if air is getting into the lines, the engine won’t start. Inspect the fuel lines carefully and replace any damaged or leaking hoses.
     
   • Air in the Fuel System: Air in the fuel system can cause the engine to turn over but not start. If air has entered the fuel lines, it can prevent proper fuel injection. To fix this, the fuel system may need to be primed by using the bleed valve on the fuel filter or injection pump.
     
2. Electrical System Problems
   The electrical system in the Case 1840 plays a crucial role in starting the engine and powering critical components. Issues with the battery, starter motor, or ignition system can prevent the engine from starting.
   • Battery Voltage and Condition: Even if the engine turns over, a weak or partially discharged battery may not provide enough power to start the engine. Ensure that the battery is fully charged, and check the terminals for corrosion. Clean any corrosion and ensure the connections are tight.
     
   • Starter Motor: The starter motor is responsible for cranking the engine. If the starter motor is faulty or worn, it may turn over but fail to engage the engine properly. Testing the starter motor and its solenoid can help identify if this is the issue.
     
   • Ignition Switch and Wiring: The ignition system and its associated wiring could also be at fault. If the ignition switch is malfunctioning, it may not send the correct signals to the starter motor or other essential systems. Inspect the wiring for any signs of wear or damage that could disrupt the electrical flow.
     
3. Glow Plug Malfunctions (Cold Start Issues)
   Diesel engines, particularly in colder weather, rely on glow plugs to preheat the combustion chamber for smooth engine start-up. If the glow plugs are not functioning correctly, the engine may turn over but fail to start, especially in cold conditions.
   • Glow Plug Failure: If one or more glow plugs fail, it can make it harder for the engine to start, as it will not heat the fuel-air mixture enough for combustion. Test the glow plugs using a multimeter to ensure they are working properly. If necessary, replace the faulty glow plugs.
     
   • Glow Plug Relay Issues: The glow plug relay controls the timing of the glow plug operation. If the relay is faulty, it may fail to provide power to the glow plugs when needed, leading to starting issues.
     
4. Fuel Injector Problems
   Fuel injectors are responsible for delivering the right amount of fuel into the combustion chamber for ignition. If the injectors are clogged or malfunctioning, the engine may turn over but fail to start because the proper air-fuel mixture is not being provided.
   • Clogged or Dirty Injectors: Over time, injectors can become clogged with carbon or other debris. This reduces the amount of fuel delivered to the engine, making it difficult for the engine to start. Cleaning or replacing the injectors may resolve the issue.
     
   • Injector Pump Issues: The injector pump controls the flow and timing of fuel injected into the engine. If the injector pump is malfunctioning, it can prevent the injectors from delivering fuel at the correct time. A faulty pump may need to be replaced.
     
5. Fuel Quality
   Poor-quality fuel or contaminated fuel can also cause starting issues. Diesel fuel that is old or has water contamination may not ignite properly, even if the engine turns over.
   • Water in Fuel: If water has entered the fuel tank, it can cause starting problems, as diesel engines rely on a consistent fuel-air mixture. Water can prevent proper combustion, especially during cold starts. Drain the fuel tank and replace any contaminated fuel with fresh, clean diesel.
     
   • Old or Gelled Diesel: In cold weather, diesel fuel can gel and become thick, preventing it from flowing properly. If this is the case, it may be necessary to add fuel additives to restore proper fuel flow or even warm up the fuel tank in extreme cases.
     
6. Faulty Sensors or ECU Malfunctions
   Modern machines like the Case 1840 often have electronic control units (ECUs) that monitor various components, including sensors for fuel pressure, engine temperature, and air intake. A malfunctioning sensor or faulty ECU can prevent the engine from starting, even though it turns over.
   • Crankshaft Position Sensor: The crankshaft position sensor provides data to the ECU to determine the timing of fuel injection and ignition. If this sensor is malfunctioning, it can prevent the engine from starting.
     
   • Other Sensors: Other sensors, such as the fuel pressure sensor or the camshaft position sensor, can also cause starting issues if they fail. These sensors provide critical information to the ECU, which controls fuel delivery and ignition timing.
     

Diagnostic Steps and Solutions

1. Check the Battery: Start by checking the battery voltage and condition. If the voltage is low, recharge or replace the battery. Clean the terminals and ensure all connections are secure.
   
2. Inspect Fuel System: Check the fuel filter, fuel lines, and fuel injectors for any clogs or leaks. Replace the fuel filter if necessary, and prime the fuel system to eliminate any air in the lines.
   
3. Test Glow Plugs: In cold weather, ensure that the glow plugs are functioning properly by testing them with a multimeter. Replace any faulty glow plugs or glow plug relays.
   
4. Inspect Electrical System: Examine the wiring and ignition switch for any signs of wear or damage. Test the starter motor to ensure it is functioning correctly.
   
5. Check for Fuel Contamination: Drain the fuel tank if you suspect water or contaminated fuel. Replace with fresh, clean diesel and add fuel additives if necessary to prevent gelling.
   
6. Consult the Service Manual: Always refer to the Case 1840 service manual for specific troubleshooting steps, wiring diagrams, and diagnostic procedures to ensure accurate diagnosis and repair.
   

Conclusion
When a Case 1840 skid steer turns over but won’t start, there can be multiple causes ranging from fuel delivery issues to electrical problems or even sensor malfunctions. By methodically troubleshooting each component—fuel system, electrical system, glow plugs, and injectors—operators can often pinpoint the problem and take the necessary steps to resolve it. Regular maintenance and attention to the machine’s fuel and electrical systems can help prevent such issues from arising and keep the machine running efficiently.