Fault Phenomenon: Volvo L90 wheel loader black smoke from exhaust during acceleration, weak during loading operations.

Troubleshooting Process:
– Checked air filter: air filter severely clogged.
– Checked turbocharger: low turbocharger boost pressure.
– Checked injector nozzles: poor atomization or dripping.
– Checked fuel: poor quality or water contamination.

Root Cause: The air filter was not replaced for a long time, causing high intake resistance and incomplete combustion, leading to black smoke.

Required Parts: Replace air filter element, check turbocharger line sealing.