The Reasons of Jammed VE Distributor Injection Pump

A VE pump plunger has both pressure fuel function and distribution function, and the rotating speed is 1000-2000 - r/mim, pumping fuel 4-6 times with every turn. The fit clearance is only 3 nm, thus it is easily jammed by slightly carelessness. The jammed locations are usually lying in two parts. One is the lag between plunger and barrel. The plunger is likely to be twist off, so it’s unable to start after the engine go out. As a result, there is no oil pump out from head rotor and also non-response for increasing throttle. 

 

Another jammed place is stuck between plunger and spill ring. Drainage ring slide on the surface of plunger does not rotate when at work. Once the stuck, ring and plunger are synchronously rotating, the ball head and speed control lever assembly won’t let the ring rotate. Therefore, under the effect of strong torque, the ball head is crowded, and the lever assembly is forcibly twisted. At the instant of jammed situation, the locating pin on the CAM plate has possibility to be cut off.

 

1. The main reason is unclear fuel.

(1) Water or corrosive liquid are mixed in the fuel, or join the diesel gasoline. 

Low quality diesel and other mistakes cause rust and destruction of lubricant film. Then, jam happens.

(2) Filter fails, small hard particles are stuck into pump and then causes jammed pump.

(3) Don’t keep the pump’s running for a long time. The pump is installed on the engine side and often stays in high temperature condition. Hydrocarbon compounds in fuel pyrolysis will mix with tiny granular which attached to the walls of each parts. Thus it will gradually accumulate into tiny particles by time. Once the particles enter into vacuum pump in high-speed precision motion, jamming occurs easily.

(4) Inner buffer block is rubber part, withstand torque impact for a long time, and constantly under impact load, easily to deteriorate and peel into scrawled particles after aging. These small granules rotary vane vacuum pump cavity, which may also make the plunger die.

 

2. Improper operation is another reason for sticking. 

Plungers operate the lubricating and cooling of the plunger sleeve in high speed on the surface of the water ring vacuum pump, a small amount of fuel releasing in the process of pump fuel distribution. Once plunger is not cooling and lubrication, serious problems may occur. For example, the magnet valve is not plugged in or electric pump work after turning on the power ; Or, when debugging cut out speed, a lot of fuel leak out from the oil ring test for bench’s long term running time without oil pumped out from distribution hole. In this case, the surface of plunger and sleeve don’t have oil lubrication and cooling, so it is likely to be stuck. 

 

3. Hot diaphragm pump make pump stuck.

Fuel pump is generally hot when work normally. Thus, the pump should not be infused in cold water to avoid the shell of head rotor shrinking, which may cause plunger clog.