How Can You Diagnose Issues with Your Common Rail Injection System?

9 October 2020
 Categories: , Blog

If you are having problems with the fuel delivery system on your car or truck, it could be something to do with the key distribution component known as the "common rail." What is this, and what issues should you be looking for?

Gathering Fuel

This part is so-called as it gathers and then distributes fuel from one source to each individual injector. All of the fuel, therefore, has to travel down a single rail, which is little more than a long metal tube. Within the tube, the pressure is built up to the required levels so that the fuel can be successfully delivered to the engine as needed.


It's very important to ensure that the fuel delivered through the common rail is as pure as possible. You need to focus on filtration and make sure that you use a filter with the most appropriate micron rating. If in doubt, always refer to the manufacturer's specification and check to see if any aftermarket products are inferior.

Foreign Objects

If impurities do get through to the fuel injection system, they can cause damage that will, in turn, lead to lower performance. These impurities will affect a small valve within the common rail system that opens and closes in order to build pressure. The valve will not function properly should tiny contaminants damage the body. These contaminants can erode the valve seat, and when this happens, it will limit the amount of fuel delivered to the motor.

If you've noticed a lot of smoke from the back of your vehicle recently accompanied by a rough sounding engine, or issues when trying to start in the morning, check the valve seat for damage.

Fuel Contamination

You will also need to ensure that you buy top-quality fuel at the pump so that you can avoid contamination at the source. After all, the parts in and around the injection system are very small and contain tiny apertures through which fuel is delivered under pressure. If the fuel in your tank is contaminated by moisture, then this will make its way through to the injectors via the common rail system. When the moisture condenses on these individual parts, it can lead to a buildup of corrosion. Once again, this could lead to issues with engine performance.

Dealing with Issues

Remember, the common rail injection tube will work perfectly well so long as it is not contaminated by either tiny impurities or moisture. If you suspect issues with your system, ask a qualified technician to take a closer look. If you need to replace parts, always ensure that you buy components that are of the highest quality.

For more information on common rail injectors, reach out to a local auto parts supplier.