Fuel Pressure – And why it’s important


Most Common fault codes:

EID:396 High Fuel Rail Pressure

-The fuel rail pressure is above an acceptable level. The code is logged. Engine power is derated. The engine may stop. 

EID:398 Low Fuel Rail Pressure

– The fuel rail pressure is below an acceptable level. The code is logged. Engine power is derated.  The engine may stop. 

Caterpillar diesel engine fuel systems are composed of a specialized set of components which must deliver the correct amount of fuel to the cylinder – at the precise moment it is needed.
A well-designed fuel system enables the engine to produce maximum power at maximum efficiency, with a minimum of exhaust emissions.

The basic fuel system consists of a fuel transfer pump, fuel filters, fuel injectors, and a fuel pressure regulator. Fuel pressure is controlled by the pressure regulating valve, and it must be able to provide the correct fuel pressure to the injectors at all times.

Today’s diesel injectors must develop very high injection pressures to function with modern high compression ratio engine designs. The fuel system is responsible for providing an adequate supply of clean and stable fuel for proper operation.

Incorrect fuel pressure may result in conditions such as:

Engine derates – Poor acceleration – Engine hesitation – Poor throttle response – No start events – Inhibited Aftertreatment system operation – and a variety of other performance concerns.

If you are experiencing performance concerns, or have any questions about your equipment – Reach out to your service representative or your local H.O. Penn branch immediately.

Be sure to inspect and service your fuel system regularly. A healthy fuel system can increase the life span of your equipment, and will ensure you always PRODUCE MAXIMUM POWER AT MAXIMUM EFFICIENCY.