ERIKC DLLA 150P 991 DENSO diesel engine nozzle DLLA 150 P991 fuel injector nozzle for 095000-6252

FAQ: Analysis of Common Failures of Fuel Injection Pumps? Fatigue and fracture

ERIKC Answer: (1) Breakage of plunger spring. The plunger spring will break during actual use, which may be due to the following reasons: 1 The axial clearance of the camshaft is too large (usually more than 2 mm) or the positioning screw of the roller transmission part is loose, causing the injection pump to work. Pulse vibration is generated, causing a violent impact between the roller transmission member and the camshaft, causing the plunger spring to break due to the impact load. The axial clearance of the camshaft should normally be controlled around 0. 10 mm. When the axial clearance is found to be too large, gaskets between the injection pump connection plate and the governor front housing and the injection pump body can be reduced. 2 When the plunger spring is installed, the pre-tightening force is too large or the spring force is uneven. 3 The plunger spring is too elastic or of poor quality. The identification method of the plunger spring installed in the body of the pump is that, if the plunger spring can be rotated by hand, it is considered that the elastic force is appropriate. 4 The positioning shoulder of the plunger spring lower seat does not properly fall into the roller drive during assembly or tilt occurs.

(2) Overhaul of springs and spring seats. When checking the plunger spring, if a crack is found, the free length is shortened by 1 mm, the twist is more than 1 mm, etc., new parts should be replaced. When replacing a new part, its elasticity should be tested. The elasticity must comply with the original regulations.

(3) If the output valve spring is distorted and the elasticity is weakened, it should be replaced with a new one. Its elasticity should be in accordance with the original regulations.