The cleaning of the fuel tank suction filter screen should not be ignored

One of the 2LTLZ4.5 type asphalt concrete pavers in our company has encountered problems such as insufficient engine power, difficulty in starting and spontaneous engine shutdown at idle during construction. Later, whenever the load of the paving operation slightly increased or when climbing a slope, the engine would stall by itself.

This paver is equipped with an F4L912 Deutz engine. Under normal circumstances, its power is more than sufficient, and the engine did not show any abnormal conditions before it shut down by itself. The initial judgment is that it is a local fuel line blockage, and the most likely cause is a clogged fuel filter.

Therefore, the fuel filter has been in use for nearly 1,000 hours and has reached the replacement period. So, it was decided to replace it with a new disposable fuel filter. However, when releasing the relief valve to expel the air in the oil circuit, during the process of pressing the diaphragm type fuel transfer pump's fuel rod several times with force, it was found that a small amount of fuel and bubbles emerged from the relief valve. The refueling speed was also abnormally slow, but there was nothing unusual about the fuel transfer hose from the fuel tank to the fuel transfer pump. This indicates that a section of the fuel passage entrance before the fuel transfer pump has been severely blocked. So I opened the flange on the upper surface of the fuel tank, took out the fuel suction pipe, and found that there was indeed a thick layer of gel-like dirt adhering to the suction filter screen. This is the cause of the local oil passage blockage in the engine.

Use a soft brush and clean diesel to scrub off the gel-like dirt adhering to the paper oil suction filter screen. Then, clean it thoroughly with gasoline, dry it with an air pump, and clean the fuel tank. Add clean diesel that has settled for more than 48 hours, reinstall the oil suction pipe and the flange at the top of the fuel tank to their original positions, and expel the air in the fuel line. When restarting the engine, if you feel that the engine's power has been restored and the idle speed is uniform and stable, it indicates that the fault has been eliminated.

This malfunction reminds us: First, it is necessary to refuel with clean diesel that has settled. Under no circumstances should we, for the sake of convenience, refuel with unsettled diesel at nearby gas stations along the way. Second, it is necessary to strengthen daily maintenance work. Disposable fuel filters should be replaced on time as required. In particular, the cleaning of the fuel suction filter screen in the fuel tank should not be neglected. The fuel tank and the fuel suction filter screen should be cleaned regularly.