Small diesel engine starting difficulty check

Author:Dekenag  Alice

The small diesel engine is difficult to start, is a common fault, if can judge and eliminate in time, not only can eliminate the vast number of hand distress, but also can give full play to its due role. Therefore, based on the phenomenon of the small diesel engine in the process of starting, this paper briefly describes the fault inspection methods and procedures:

First, during the starting process, check the fuel system to see if the injector can make a squeaky sound. If the sound of fuel injection is not heard, the fuel entering the cylinder is weak. At this point, the pump can be loose to see if there is oil out.

1. If there is no oil flowing out, indicating that the low-pressure oil path is abnormal, check whether the oil tank is filled, whether the filter is blocked, whether the oil cover is ventilated and whether the oil path has air. After troubleshooting, until the fuel flow out, then screw down the air screw.

2. If fuel oil flows out, it indicates that the low-pressure oil path is normal. Faults often occur in high-pressure oil roads (such as injection pump, nozzle, etc.). At this point, the high-pressure oil pipe should be removed and further inspection should be made:

(1) Turn the engine and put the throttle at maximum. When there is no intermittent fuel coming out at the oil outlet joint of the fuel pump, the fuel injection rack is usually stuck or the plunger spring is broken. The fuel pump should be removed from the engine for maintenance. In addition, 190 diesel engines, if the speed lever screw is loose or the speed control disc is installed in reverse (the front side of the engine should be installed with shoulder), cause the speed control fly ball to fall, force the rack stick of the fuel injection pump to be stuck in the stop position, and also cause the fuel injection pump out of the joint without interruption.

(2)Turn the engine and push the throttle to the stop position, such as oil flow at the oil outlet joint of the fuel injection pump. The oil outlet joint should be unloaded at this point. If the spring of the oil outlet valve is not found broken, the oil outlet valve and seat must be cleaned before loading.

(3)Cylinder, such as high-pressure oil pump intermittent oil supply, should be removed injector, with the high-pressure oil outside the pump body to connect it with the high-pressure oil pump, rotating the engine, to observe the injector injection. If the injector does not spray oil, the fuel injection pressure adjustment screw can be slightly loose. If there is fuel flow, it indicates that the nozzle needle valve and valve body guide part are seriously worn, or the joint surface of the nozzle and the injector body is not smooth, resulting in fuel leakage. If the adjusting screw is fully unscrewed, the nozzle is stuck in the closed position. The fuel injector sprays into a line, can not atomize, oil break is not simply, then the injector pin valve stuck in the open position; The fuel injector sprays oil, but is weak, and is accompanied by severe drop phenomenon, indicating that the sealing surface of the nozzle is not tight; If the nozzle pressure adjusting screw is unscrewed, the fuel injection, but the injection is weak, and slightly tightened, the injector does not spray oil, indicating that the plunger is seriously worn, should be repaired or replaced.

Secondly.During the starting process, if the sound of "squeak" fuel injection of the injector can be heard, the injection is good. But still can not start, should check the oil supply time. In addition, if the starting hole in the eddy current chamber is blocked by carbon, the engine is difficult to start.

Thirdly.If the above conditions are normal and the engine is still difficult to start, the cylinder pressure should be checked according to the regulations, because insufficient pressure is also one of the reasons causing the difficulty in starting.

Fourthly.The clogging of the air inlet pipe or air filter will also cause difficulty in starting, which is expected to attract sufficient attention during inspection.

Fifthly.Cold weather is also a factor that makes starting difficult. Therefore, in the cold season, the machine must be pre-heating before starting, before starting the machine.