The tractor fuel pump is an critical important component in dhe diesel engine system.Its performance directly influences the performance of the whole diesel engine.So we should have a preliminary understanding on its problems and related solution.Below diesel injection system spare parts supplier - China Balin Power Co.,Ltd will introduce two main faults and its solution:

 

(1)The plunger is not flexible or stuck in the plunger sleeve

Failure Causes 

1.Plunger between plunger tappet adjusting screws (or in the spring) small gap up and down, or no gap 

2.There is no gap between the plunger sleeve and upper body bore, which causes the plunger sleeve to deform.

3.The plunger barrel positioning screw is overtightened on the plunger barrel  to deform the plunger barrel 

4.When the plunger and plunger sleeve are cleaned and assembled, the surface is not clean or the edge collides, resulting in burrs and deformation.

5.The tightening torque of deliver valve seat is too large, which causes the plunger to deform

6.Diesel oil is not clean and mechanical impurities enter the mating surface

7.The oil inside the fuel pump shell is too dirty

8.Plunger tappet assembly height is too high, resulting in the plunger at the top stop, the plunger and the deliver valve seat clearance is too small, or even no gap, resulting in collision, resulting in the deformation to the plunger head edge.

 

Solution:

1.When the plunger is paired with the plunger sleeve, it is not allowed to replace any of the parts.The plunger tip and screw groove should be kept at an acute Angle and no damage is allowed. The ground matching surface should be thoroughly cleaned with clean diesel before assembly.Check the uniform rotation and movement of the plunger in the plunger sleeve.Over a third out of plunger sleeve, when placed in a vertical position or 45 ° inclined position, plunger (with adjusting arm) in any corner, under the action of dead weight, should be able to freely and seamlessly slipped in the plunger sleeve.

2.After positioning the plunger barrel with the positioning screw, the plunger should be able to move up and down but not to rotate

3.Tighten the delivery valve seat according to technical requirements.

4.After the clamping spring is used to limit the plunger and plunger spring, the gap between up and down shall be 0.2-0.55mm.The plunger, together with the plunger spring seat, is placed on the plunger tappet adjusting screw. The clearance between the plunger  should also be 0.2-0.55mm

5.The clean oil should be added to the shell of the fuel pump, and its cleaning degree should be checked regularly

6.Assemble the plunger tappet according to the technical requirements. When the plunger is at the top stop, there should be a minimum gap of 0.3mm between the plunger and the delivery valve seat.

 

(2)Two cylinder oil quantity in Oil pump is uneven

The reason of uneven oil supply of two cylinders, besides improper adjustment, there are also reasons from the plunger spring, deliver valve spring, injector spring permanent deformation or break, needle valve coupling, deliver valve coupling, plunger coupling two cylinders wear not uniform, or pull rod fork and arm wear not uniform, or loose caused by.

 

Solution:

Re-adjust the oil supply and injection pressure to make both cylinders even, or replace or repair damaged parts.No matter that it is repaired or replaced, the injection pressure and fuel supply should be adjusted finally.

 

When it is necessary to adjust the uneven oil quantity, put the adjusting gear lever at the stop supply position, adjust the locking screw on the gear with the screwdriver screwdriver, and then touch the screwdriver head in the hole of the oil control sleeve, and then hammer the screwdriver handle.Turn the sleeve to the left when it's too little oil;Turn  to the right if too large.Adjust until to the standard.When reassembly, pull the adjusting gear lever to the maximum oil supply position, so that the center line of clamping and controlling sleeve groove and plunger lug are consistent with the center line of the pump body's top hole.When all plunger keep same,your work is done.