How does a fuel rail work?
The fuel rail delivers fuel from the pump to the injectors, and the rail pressure sensor measures the pressure in the rail and sends a signal back to the engine control unit (ECU) indicating the current pressure in the rail. The medium-pressure pump is typically cam driven as can be seen in this video.
What does a fuel metering valve do?
To adapt the fuel pressure in the rail, the fuel metering valve on the mechanical fuel pump controls the amount of fuel entering the pump. The plunger is held fully open by a spring to let fuel pass through.
What warnings must followed when working around common rail fuel systems?
New common-rail engine fuel pressure is so high it can literally slice skin like a scalpel. While you should never attempt to bleed anything past the secondary fuel filter on a common-rail diesel, you really shouldn’t have to. Such engines typically bleed themselves.
What causes common rail failure?
Water contamination: Another common cause of Common Rail injector failure is contamination from excess water in the fuel. If not stored or handled correctly, water can enter the fuel and will react with the chemicals in it to corrode metal surfaces and reduce lubrication between the moving parts.
What does check engine light on fuel rail sensor mean?
Check Engine Light comes on The fuel rail sensor, commonly referred to as the fuel pressure sensor, is an engine management component that is commonly found on diesel, and some gasoline injected vehicles. It is a part of vehicle’s fuel system and designed to monitor the fuel pressure that is present at the fuel rail.
Can a fuel rail pressure sensor be replaced?
If you have some mechanical experience, replacing the fuel rail pressure sensor is a good DIY candidate. Note: Do not confuse the fuel rail pressure sensor with the fuel tank pressure sensor.
Are there any problems with common rail fuel systems?
Although common rails are an improvement from prior types of fuel systems, they’re not without their issues. Many of these problems, however, stem from things unrelated to the design of a common rail system, which common rail owners should be aware if they want to minimize expensive repairs.
Why do engines use returnless fuel injection systems?
Consequently, diagnosis is similar. Returnless EFI systems typically operate at a higher pressure than return-type systems. This is necessary to reduce the risk of fuel boiling and vapor lock in the injector supply rail during hot weather (since there is no recirculation of fuel from the engine back to the tank to keep the fuel supply rail cool).