Fuel System


Volvo engines do a superb job of keeping fuel temperature regulated, allowing them to operate more efficiently for better fuel economy and lower operating costs.

Engine fuel systems are divided into low- and high-pressure zones. The low-pressure zone filters and supplies fuel to the high-pressure zone, which injects fuel into the cylinders. The cam actuates the injector plunger and produces the high pressure needed to inject atomized fuel for an efficient burn. The fuel injector solenoid valve allows the fuel to be injected or bypassed.

Injectors feed fuel to the engine based on volume. Heated fuel is less dense (less BTU per volume), and therefore, engine performance decreases as fuel temperature increases. Addition of fuel coolers—which also add cost and complexity—can compensate for the increased heat.

Volvo engines do not require fuel coolers. Our system draws fuel from the tank through a 20–40 micron primary filter. It then passes through and cools the ECU as it heads toward a fuel exchange at the top front of the engine cylinder head. At that connection, excess fuel from the injectors is mixed with the incoming fuel and pumped through a 3–5 micron secondary filter. The fuel is then sent to the injectors at the rear of the cylinder head.

Because our system draws only the amount of fuel needed for combustion, the fuel temperature is not increased with large amounts of return fuel. The recirculated fuel’s temperature is maintained by engine coolant, which has better regulation than return fuel.