Wearing of valve, piston ring, cylinder sleeve wear cause the force of compressing not enough which means its pressure and temperature can't meet the requirement.The combustion of diesel fuel can't be complete.It brings the black smoke.

 

2.1 The quality of combustion chamber itself will effect a lot after long serving time.Meanwhile the space between compressing  will also change the shape and volume of combustion chamber.It cause poor mixture of diesel fuel and air which is necessary to have a complete combustion.

 

2.2 Wrong install of piston

It result in that coordination in injectors,combustion chamber and air inlet is destroyed.It can't make good gas mixture.Incomplete combustion happened.

 

There are three main aspects to show the performance of injector:Poor spraying ability,Insufficient injection pressure and injector drips.All of them can cause the incomplete combustion between diesel fuel and air in the cylinder.

 

We may say that it's the primary cause of the black smoke.It can be caused by diesel fuel injector wear that enlarges the nozzle hole or erodes the injector needle and allows excess fuel to flow into the combustion chamber.It can also be caused by the poor quality nozzles you purchased to install in injector.In many cases the nozzle and needle wear is due to corrosion from contaminated or high sulfur diesel fuel.Here we would advise genuine BASCOLIN brand nozzles which stands for assured quality.Every piece of nozzle is tested before delivery.It guaratee 100% outstanding performance when customers receive and use.

 

5.1 Angle too big:

For those cirect injection diesel engines,by increasing the spray angles properly could reduce exhaust smoke in the basis that other parameters remain unchanged.While premature injection diesel fuel is not good for its evaporation and mixing then black smoke appear.

 

5.2 Angle too small

If the injection too late,there will be a part of fuel not ready to form combustible mixture but is put into the process of high temperature decomposition, combustion within exhaust pipe.Finally the black smoke come out together with exhaust gas.

 

Too large resistance brings insufficient air intake and incomplete exhaust.

 

Excessive clearance of the valve reduces the maximum valve opening and the opening time which result in insufficient air intake.In the other side,if the valve clearance is too small, the valve is easy to leak.It will affect cylinder compression force.In both cases, the proportion of air in the mixture decreases, resulting in incomplete combustion.

 

The engine distribution phase changes due to component quality and assembly quality.It will cause changes in the opening and closing time of the valve.Finally it affects the combustion process of the engine.By the way,the serious gas distribution phase change will lead to the serious accident of the valve against the piston.

 

9.1 Plunger or Deliver Valve problem:

Severe wear of individual or all plunger or deliver valves on the fuel pump will result in a drop in pump pressure,So that the pressure of the injector (nozzle) is relatively delayed, the fuel injection is delayed and the afterburning is increased, so the diesel engine emits black smoke.

 

9.2 The fuel supply quantity of each subcylinder of the fuel injection pump is not uniform and the fuel supply angle is inconsistent.

The diesel fuel supply is not uniform,.some cylinder diesel fuel supply is large,while some others is small,.For those too large diesel fuel supply in cylinder,its combustion is not complete, exhaust smoke;The tank with small diesel fuel supply is unable to work.

If the fuel supply angle is inconsistent. it leads to some tanks supplying fuel early, some tanks supplying fuel late.Because usually one cylinder is used as the benchmark when adjusting the oil supply advance angle in daily life, the consistency of the oil supply advance angle is generally not valued by people.

 

If the diesel you are using is not clean or in poor quality,the performance can't reach the requirement,bringing poor combustion.

 

If your truck has the black smoke problem,you could check the probable reasons above