Deutz-Fahr 1326 – EMR3: Misfire Detected in Cylinder 4

The engine control module has detected a misfire in cylinder 4 by monitoring the rotational speed of the crankshaft. A momentary slowdown in rotation indicates that the combustion process in this specific cylinder is incomplete or absent, which can lead to a loss of engine power, increased emissions, and rough engine operation.

• Agrotron series
• Agrotron 106-165 MK3

1. 1

   Visually inspect the area around cylinder 4 for damaged wiring, loose connections, or fuel leaks around the injector

2. 2

   Review other fault codes using a diagnostic scanner (multiple misfire codes like P0300 indicate systemic issues such as low fuel pressure, a vacuum leak, or a faulty sensor rather than an isolated cylinder 4 problem)

3. 3

   Check diesel fuel quality to ensure it is clean and not contaminated with water or dirt

4. 4

   Inspect fuel filters for clogs or dirt that could restrict fuel flow

5. 5

   Examine the air filter for clogs that could restrict airflow to the engine

1. 1

   Check for Spark (on applicable engines)

   While most Deutz agricultural engines are diesel and use compression for ignition, some models might have glow plugs to aid in cold starting. If applicable, check the functionality of the glow plug for cylinder 4.

2. 2

   Swap Ignition Components (if applicable)

   For engines with individual ignition coils, swap the coil from cylinder 4 with one from an adjacent cylinder (e.g., cylinder 3). Clear the fault codes and run the engine. If the misfire code moves to the new cylinder (e.g., P0303), the ignition coil is faulty and should be replaced. The same process can be applied to the spark plug if present.

3. 3

   Inspect and test the fuel injector

   Check the wiring harness and connector to the fuel injector for cylinder 4 for any signs of damage, corrosion, or loose connections. Swap the fuel injector from cylinder 4 with another cylinder to see if the fault follows. Alternatively, have the fuel injector professionally tested for spray pattern, atomization, and flow rate.

4. 4

   Perform a compression test

   Test compression on cylinder 4 and compare it to the other cylinders. A significant drop in pressure indicates a mechanical problem such as leaking valves, worn piston rings, or a damaged piston.

5. 5

   Check for vacuum leaks

   Inspect all vacuum hoses and the intake manifold gasket for any leaks that could be introducing unmetered air into the intake system, which can disrupt the air-fuel ratio and cause misfires.

6. 6

   Reset the ECU

   After performing any repairs, switch the ignition off, wait for the ECU to fully power down, and then switch the ignition back on. After the reset, check if the fault code reappears.