High Quality Delivery Valve F210 Diesel Engine Spare Parts

Preliminary judgment through engine operation symptoms
The abnormality of the oil outlet valve will directly affect the pressure, time and stability of fuel injection, which can be initially associated through the following typical symptoms:

Abnormal power and fuel consumption
The power is significantly reduced, the acceleration is weak, and the fuel consumption is significantly increased (due to poor atomization and incomplete combustion).
The exhaust pipe continues to emit black smoke (incompletely burned carbon particles) or occasionally emits white smoke (late injection leads to unburned fuel vapor).
Poor operation stability
Severe shaking at idle speed, high and low speed ("wandering"), and even accompanied by periodic "knocking" sound (metal knocking sound, due to abnormal combustion timing).
There is a setback during acceleration, the speed increase is not smooth, and the symptoms are aggravated when the load increases (such as climbing).
Starting and flameout problems
Cold start is difficult, and multiple oil pumping or long preheating are required (may be due to insufficient pressure caused by leakage of the oil outlet valve).
When restarting after shutdown, air must be re-exhausted to ignite (due to poor sealing of the oil outlet valve, fuel backflow and air entering the oil circuit).

Secondary injection or dripping characteristics
The exhaust pipe occasionally makes a "cannon" sound (the secondary injected fuel burns during the exhaust stage).
After stopping, observe the vicinity of the injector. If there is oil stain or fuel dripping (after eliminating the leak of the injector itself), it may be a leak in the oil outlet valve.

Basic inspection: eliminate interference from other components
The symptoms of abnormal oil outlet valve may be confused with faults such as the injector, injection pump plunger, and fuel filter. Other possibilities must be eliminated first:

Check the fuel quality and filtration system
Confirm that the fuel is free of impurities and moisture (it can be checked by draining water from the oil-water separator), and the fuel filter is not blocked (blockage will cause insufficient fuel supply, and the symptoms are similar to those of oil outlet valve failure).
If the fuel is seriously contaminated, replace the fuel and filter first, and then observe whether the symptoms are relieved.
Check the status of the injector
Disassemble the injector, observe its spray shape (normal should be a uniformly atomized cone, abnormal should be oil droplets and deflection), and test the injection pressure (whether it meets the standard).
If the injector itself is worn or stuck, it will also cause similar symptoms. The injector needs to be repaired or replaced before judgment.
Check the high-pressure oil pipe and joint
Check whether the high-pressure oil pipe has cracks and whether the joint is loose (leakage will cause pressure drop). If necessary, replace the new oil pipe for testing.
Targeted detection: Focus on the core characteristics of the oil outlet valve
After eliminating other component failures, the following methods are used to directly detect the sealing, pressure relief function and movement flexibility of the oil outlet valve:
1. Oil outlet valve sealing test (key indicators)
Tools: injection pump test bench (professional equipment) or simple pressure testing device (such as manual pump pressure tool).
Method:
Remove the oil outlet valve pair (oil outlet valve and valve seat), clean them and reinstall the test device.
Apply standard pressure to the oil outlet valve (such as 10MPa, determined according to the engine model) and observe the pressure maintenance:
If the pressure drops rapidly (such as a drop of more than 1MPa within 10 seconds), it means that the sealing cone is worn, carbon deposited or deformed, and the sealing is poor.
If the pressure remains basically stable, the sealing is normal.
2. Pressure relief ring function test
The pressure relief ring of the oil outlet valve (the cylindrical surface near the top) is used to reduce the residual pressure of the high-pressure oil pipe after the injection is completed to prevent secondary injection.
Method:
On the injection pump test bench, measure the change in the residual pressure of the oil pipe after the oil outlet valve is closed.
If the residual pressure is too high (more than 5% of the standard value) or drops slowly, it means that the pressure relief ring is worn (the gap is too large) and the function fails.
Simple judgment: After disassembly, observe the pressure relief ring. If there are obvious scratches, wear or step-shaped deformation on the surface, it can be directly judged as abnormal.
3. Oil outlet valve jamming and flexibility check
The oil outlet valve needs to be opened/closed flexibly under the action of the spring. Jamming will cause delayed action.
Method:
Remove the oil outlet valve and push the valve core by hand. Normally, it should be able to move smoothly in the valve seat without jamming or jamming.
Observe whether the valve core and valve seat are jammed by impurities (such as metal debris, colloid), or traces of ablation and adhesion caused by long-term high temperature.
Check the oil outlet valve spring: If the spring is broken, the elastic force is weakened (measured by a dynamometer) or deformed, it will cause abnormal opening/closing pressure and needs to be replaced simultaneously.
4. Single cylinder oil cut-off test (applicable to multi-cylinder engines)
If the oil outlet valve of a certain cylinder is suspected to be abnormal, it can be located by the "oil cut-off method":
When the engine is idling, close the high-pressure oil pipes of each cylinder one by one (or disconnect the injector solenoid valve).
If the engine shake does not change significantly after closing a certain cylinder (or becomes more stable), it means that the oil supply of the cylinder is abnormal, which may be a failure of the oil outlet valve (further confirmed in combination with other symptoms).

Professional equipment detection: fuel injection pump test bench verification
For accurate judgment, it is necessary to use the fuel injection pump test bench (commonly used in repair shops), which can simulate the fuel supply status of the engine at different speeds:

Measure the fuel supply pressure curve
The fuel supply pressure of a normal oil outlet valve should rise steadily with the speed, and the curve should be smooth; if the pressure fluctuates greatly, the peak value is lower than the standard or drops too fast, it means that the oil outlet valve is poorly sealed or the pressure relief ring belt fails.
Detect injection timing
The test bench can measure the opening time of the oil outlet valve of each cylinder. If the deviation from the standard timing exceeds ±1° crankshaft angle, it means that the oil outlet valve (or its spring) is abnormal, causing the injection to be advanced/delayed.
Observe the duration of injection
If there is still fuel leakage after the injection is completed (manifested by the injection duration being too long), combined with the pressure curve, it can be determined that the oil outlet valve is not closed tightly or the pressure relief ring is worn.
Summary: Judgment process suggestions
First, preliminarily suspect the oil outlet valve problem through engine symptoms (black smoke, shaking, power reduction).
Exclude other component failures such as fuel quality, filter, and injector.
Disassemble and inspect the oil outlet valve pair, check the sealing surface, pressure relief ring, and spring status, and perform sealing and flexibility tests.
If necessary, quantitative detection is performed on the injection pump test bench to finally confirm the fault.