Abstract.
Following the description of the agricultural diesel engine failure in the previous article, this paper will elaborate on the other three troubleshooting, respectively, the fuel injection pump rack deformation and damage, the shutdown solenoid valve not being strictly closed, and the throttle control mechanism improperly adjusted. If you are interested in this article, you can read on.
4.The fuel injection pump rack is deformed and damaged
First, the fuel injection pump rack is stuck. Due to poor assembly or bending deformation of the rack, the fuel injection pump rack is stuck, and the plunger of the fuel injection pump can not turn, so the oil supply can not be stopped, resulting in the diesel engine not being turned off. At this time, the fuel injection pump should be disassembled for inspection and repair. If the fuel injection pump rack is bent and deformed, it can be straightened by tapping on the platform, but the surface must not be damaged; If the rack and gear mesh are not good, you can use a small file for local correction; If it is due to improper assembly of parts, it should be corrected.
Second, the handle on the fuel injection pump rack falls off. The diesel engine fuel injection pump rack on the convex handle is welded on, due to poor welding or excessive force and fall off, it will make the throttle control handle not pull the fuel injection pump rack move, can not make the fuel injection pump change the amount of oil, resulting in diesel engine can not be turned off. At this time, the fuel injection pump rack should be replaced or the lug should be welded again. However, the repaired or replaced fuel injection pump rack must be able to mesh well with the adjusting gear and be flexible.
5.The shutdown solenoid valve is not tightly closed
The shutdown solenoid valve is not strictly closed, which is one of the main reasons for the difficulty of diesel engine flameout. When the key is turned off, that is, the power supply to the solenoid valve is cut off, the solenoid valve should be closed, and the oil passage of the fuel to the cylinder head is sealed; If the shutdown solenoid valve is not tightly closed, a small amount of fuel will continue to flow to the cylinder head oil passage, so that the diesel engine can not be extinguished.
The shutdown solenoid valve is not strictly closed, in addition to processing reasons, and the cleanliness of the fuel is also very much related. When the fuel cleanliness is low, impurities will invade the solenoid valve, pad the valve disc, or make it move stuck, resulting in loose closing; Impurities may also be directly invaded by not paying attention to the cleanliness of the oil circuit during maintenance.
When it is difficult to turn off the solenoid valve because it is not tightly closed, you can often increase the throttle to impact the valve plate, so that the oil circuit is closed and the engine is turned off immediately. After the fault occurs, it should be eliminated by cleaning the solenoid valve, but the most important thing is to improve the cleanliness of the fuel, otherwise, the fault will occur repeatedly.
6.The throttle control mechanism is improperly adjusted
When the vehicle throttle control handle is in the position of maximum fuel supply, the external lever control arm of the governor should collide with the high-speed limit screw, thereby limiting the maximum fuel supply and the maximum speed. When the throttle control handle is pulled to the flameout position, the outer lever control arm of the governor collides with the low-speed limit screw to make the diesel engine flameout.
If the position of the high-speed limit screw and the low-speed limit screw is improperly adjusted, or the length of the governor external lever control arm is improperly adjusted, so that the travel of the throttle control handle is too small, the throttle control lever has not been pulled to the position that the fuel injection pump stops supplying oil, the governor external lever control arm will collide with the low-speed limit screw, and the fuel injection pump is still in the state of continuing to supply oil. The diesel engine can't be turned off. At this time, the position of the low-speed limit screw should be adjusted or the length of the governor external lever control arm should be adjusted, so that when the fuel injection pump is in the stop position, the low-speed limit screw will collide with the governor external lever control arm.
Conclusion
Combined with the above three points, the troubleshooting of agricultural diesel engines has been fully described, if you have additional or you have needs for agricultural machinery accessories, you can contact us at any time.
Relating reading:How to diagnose and rule out the failure of agricultural diesel engines?(1)