Common rail diesel starting problems
There is a big difference between a conventional diesel engine and a common rail diesel engine in how the system works to make the engine start and run. Conventional diesel engines work mechanically while common rail diesel engines work computerized, primarily regulating fuel supply to the combustion chamber.
However, some basic things can be similarities between conventional diesel engines and common rail diesel engines related to the problem of the engine being difficult to start. It cranks but doesn't start the engine.
For diesel engines with a common rail system, this engine problem includes many things: sensors, actuators, harnesses, injectors, ECMs, and others. It could be the same way of repair, but it does not necessarily produce the same results.
We need a compatible scanner with the vehicle type and brand to handle this problematic common rail diesel engine. Without a scanner, repairing this common rail diesel engine will be even more difficult.
This article will share information about the causes of the common rail diesel engine being difficult to start. Check out the causes of the common rail diesel engine is difficult to start below.
1. Problems with the fuel (Petrodiesel)
The first common cause of the common rail diesel engine is difficult to start that often occurs is a problem with the petrodiesel. Yes, this fuel problem is not only a problem for common rail diesel engines, but for conventional diesel engines, it can also be a common problem causing difficult engines to start.
However, common rail diesel engines tend to be more problematic when dealing with diesel fuel problems. Here are some problems with petrodiesel that often occur and become a problem for common rail diesel engines.
-.Petrodiesel is dirty and mixed with water
Dirty diesel fuel mixed with water can make the fuel difficult to burn and make the engine difficult to start. In addition, dirty diesel fuel mixed with water can also cause rust, mud, wear and tear on the supply pump and injector components, which will damage the common rail system.
-.Incorrect fuel type
The wrong type of fuel is often the cause of the common rail diesel engine being difficult to start. Yes, diesel engines require petrodiesel as their fuel, but in many cases, consumers fill the fuel tank with gasoline fuel, causing the engine to become difficult to start and even break down.
-.No fuel in the tank
The last thing that becomes a fuel problem that causes the common rail diesel engine to have difficulty starting is that the fuel is empty. So, before checking the problem on this hard-to-start common rail diesel engine, make sure the fuel is available in the tank.
2. Pipelines and fuel hose are torn, loose, or leaking
The next cause of the common rail diesel engine is difficult to start: the pipeline and fuel hose being torn, detached, or partially leaking. The condition of the fuel line will also disrupt the flow of fuel going to the injectors.
If the fuel pipe and line damage occur before the supply pump, the fuel will generally be mixed with outside air, making the line after the damage only filled with air or partially filled with air. The result is clear, the fuel will not get to the injectors, and the engine becomes difficult to start.
If damage to the fuel pipe and line occurs after the supply pump, there will be a fuel leak. Fuel will appear scattered in the engine precisely around the location of the leak. Besides being dangerous, this leak can also cause the engine to be difficult to start.
3. The fuel filter is clogged
The next cause of the common rail diesel engine is difficult to start due to a clogged fuel filter. Usually, if this clogged fuel filter occurs, the check engine lamp indicator or water separator warning lights up. A clogged fuel filter will affect the supply of fuel to the injectors so that it often makes the engine difficult to start.
4. Bad priming pump
Some common rail diesel engine models still use a priming pump to help the supply pump work to suck fuel from the fuel tank. Not infrequently, the priming pump also often experiences problems, causing the fuel from the tank cannot be sucked in to be channeled to the supply pump.
5. A Bad supply pump
A bad supply pump problem is often the cause of the common rail diesel engine being difficult to start. The supply pump functions to pump the petrodiesel into the fuel rail to create high pressure in the fuel rail. After the high pressure is available, the fuel is ready to be injected by the injector into the combustion chamber.
Many damage models can occur to the supply pump, ranging from damage due to the wear of components to malfunctions in the sensors and actuators in the supply pump. However, from the experience that we know, the following two things are often the cause of the common rail diesel engine being difficult to start.
-.SCV damaged, clogged, stuck, or leaking
In the supply pump, there is a component called SCV (Suction Control Valve). This component serves to regulate the fuel pressure in the fuel rail. If the SCV is damaged, clogged, stuck, or leaking, this can also be why the common rail diesel engine is difficult to start. We should note that a damaged SCV often makes the check engine warning light turn on with the DTC code P0089 or P0628.
-.The supply pump has not been initialized
Especially for replacing the supply pump with a new one or a disassembled one but still in good condition, the new supply pump must be initialized to the Engine Control Module (ECM). If initialization is not carried out, this condition often results in DTC P1275 accompanied by the check engine warning light turning ON. The effect is the engine becomes difficult to start.
6. Problems with the fuel rail (Delivery pipe)
The next cause of the common rail diesel engine is difficult to start is a problem with the fuel rail (the delivery pipe, which is often called common rail). Inside the fuel rail, two primary components regulate and monitor fuel pressure conditions before being injected by the injector. These components are the Fuel rail pressure limiter and the Fuel rail pressure sensor.
If both components are damaged or have problems, the ECM reading of the fuel pressure in the fuel rail will be inaccurate. As a result, they often turn on the check engine light and make it difficult for the engine to start.
7. Problems with the injector
The injector on a diesel engine plays a very important role, especially for converting pressurized fuel into fuel mist so that the engine can work properly.
No exception for the common rail diesel engine; without the injector that can work properly and correctly, the engine will have problems. One example is the engine is difficult to start. Here are some issues that often occur in diesel engine injectors:
-.Clogged injector
Clogged injectors often occur due to dirt in the fuel entering the nozzle hole. Clogged injectors cause fuel not to be injected/misted perfectly, making the engine difficult to start.
-.The injector has not been registered with the ECM
Especially for common rail diesel engines, injector replacement requires registration to the ECM. In the injector, there is an ID that we must enter manually into the ECM using an engine scanner. Without registration with the ECM, we can also use injectors, but they can generally cause problems such as the engine difficult to start.
-.The injector has not been learned
In addition to injector registration to the ECM, injector learning also needs to be done. Learning is the process of introducing the ECM to the condition of the newly installed injector. This learning process must be carried out if the injector is replaced with a new one. Without learning injectors, common rail engine problems are very likely to occur.
8. Bad common rail sensors
The common rail diesel engine has a system similar to the EFI system. This system uses sensors as a reference to operate the injectors and various other actuators associated with the common rail system.
If one or more of the sensors are damaged, the check engine lamp will light up, indicating a malfunction in the system. There are several sensors that we know can be the cause of the common rail engine being difficult to start, namely:
- Crankshaft position sensor which will measure the crankshaft rotation angle
- Camshaft position sensor which functions to measure the angle of rotation of the camshaft
- Manifold Absolute Pressure sensor, which serves to measure the pressure in the intake manifold.
If the three sensors are damaged, generally, the common rail diesel engine will be difficult to start. You need an engine scanner to make sure which sensors are damaging.
9. Problems with the Engine Control Module (ECM).
ECM problems are also often the cause of common rail diesel engines difficult to start. The ECM controls the entire common rail system that will read, process, and decide which components must work according to the engine's needs.
Here are some examples of problems with the ECM that can cause a common rail diesel engine to have trouble starting
-.ECM damaged
A damaged ECM will make the engine difficult to start and even make the car break down and can't be started.
-.Vehicle Identification Number (VIN) has not been registered in the ECM
If the ECM is replaced with a new one. The VIN of the car must be registered immediately (inputted) into the ECM. Without a VIN registration, generally, the ECM cannot function normally, one of which is the engine being difficult to start until it doesn't turn on.
-.The new type of ECM used does not match the model and type of vehicle
Using a new ECM (removed from a car of the same type but with a different model type) can also cause the engine to be difficult to start. It's a good idea to use the same ECM and have input the VIN on the new ECM.