What Causes Diesel Engine Reverse Rotation?

[VonKhloe]

The reasons for diesel engine reverse rotation are: 1. Overly advanced fuel injection timing: The fuel injector sprays diesel into the cylinder before the piston reaches the compression top dead center. The combustion of diesel pushes the piston downward, causing the crankshaft to rotate in reverse. This situation can be corrected by adjusting the fuel injection advance angle according to specifications when the diesel engine is shut down. 2. Excessive compression ratio: Incomplete combustion of diesel or engine oil forms carbon deposits in the combustion chamber, reducing its volume and increasing the compression ratio. During hand-cranking startup, the piston fails to pass the top dead center, causing reverse ignition. This can be resolved by removing carbon deposits to ensure a normal compression ratio. 3. Low fuel injector pressure: Insufficient fuel injector pressure leads to premature injection and combustion, resulting in engine reverse rotation. The fuel injector pressure should be checked and adjusted to meet specified values. 4. Excessive hand-cranking before startup: Too much diesel accumulates in the cylinder, causing premature combustion during startup and leading to reverse engine operation.