Injection Pump: All Facts You Should Know

An Injection Pump is a device that pumps fuel into the cylinders of a diesel engine. In the past, the injection pump was driven indirectly from the crankshaft by gears, chains, or a toothed belt that also turns the camshaft. Continue reading, you will learn more facts about injection pumps.

What is a Fuel Injection Pump?

A fuel injection pump is a machine that injects fuel into the engine cylinders of gasoline or diesel engines. Typically, a chain or toothed timing belt powered by a crankshaft’s gears drives a pump. The camshaft and this system are intertwined because of their connection. It rotates at half the speed of the crankshaft in conventional four-stroke engines to enable the proper timing of the injection process. This occurs just before the cylinder’s compression stroke starts.

What Are the 2 Kinds of Injection Pumps?

A diesel fuel injection pump is coordinated by the timing belt of the engine to introduce fuel into the engine just before the cylinder’s compression stroke reaches the top. A distributor pump, also known as a rotary pump, is another kind of fuel injection pump that is typically found in small cars and trucks.

What Are Injection and Delivery Stages in Inline Injection Pumps?

The injection phase in this type of pump is created by the position of the cams located on the camshaft of the pump itself. A pumping component that produces the injection pressure for a single engine cylinder is controlled by each cam. The rotation of a by-pass on the pumping element that controls the delivery is controlled by that element. When the delivery is low, the by-pass opens after a very brief pumping element stroke, and when the delivery is high, the by-pass opens after a longer pumping element stroke.

Excess diesel is sent back to the pump inlet through a low-pressure diesel recovery channel. The various mechanisms that regulate (rotate) the diesel delivery are connected to a rack and pinion rod that simultaneously moves all the regulators of the various pumping units (4-6-8-10 etc., depending on the type of pump). This gear rack is moved by two elements: the accelerator pedal and the idle and maximum centrifugal regulator. On turbocharged engines, an additional element on the inline pump consists of a pneumatic valve connected by a small tube to the boost circuit. As the turbo boost pressure rises, this system is meant to enrich the injection delivery. This system is similar to that employed in fully mechanically controlled rotary injection pumps.

In electronically controlled inline injection pumps, there is no centrifugal regulator of idle and maximum speed because the delivery control (and thus the idle and rev-limiting speed) is delegated to the Engine control unit (ECU, or EDC), which controls the pump through PWM electrical control (for instance, on some John Deere injection pumps). Any inline injection pump in which the injection stage is also electronically controlled by the injection control unit is subject to the same rules. Also, in this case, like with electronically controlled rotary injection pumps (if you want to learn more about this topic, read the article https://seletron.com/it/news/83_funzionamento-centraline-aggiuntive-vp37 that explains precisely how this type of pump works in detail), there is a sensor that detects the diesel delivery position and provides the In order to control this parameter precisely, an ECU with the required feedback should be used as the feedback loop.

The few chip-tuning additional units for inline injection pumps act on the values of this sensor to change the feedback and increase the injection delivery (thus torque and power) accordingly. To limit peak readings by the ECU or EDC, additional chip tuning unit controls may be on the boost pressure sensor. Therefore, its purpose is to prevent engine ECU recovery rather than necessarily acting actively to boost performance. This kind of injection pump was not frequently used in automobiles even in the past. Inline injection pumps were used extensively on heavy-duty trucks and transportation engines in general, but also on EMM (earth-moving machinery) and marine engines, all of which the common-rail injection system later entered.

What Causes Injector Pump Failure?

A major cause of fuel injection pump problems is the use of dirty fuel. Residue accumulates in every part of your body over time. This problem is made worse by using fuel of poor quality. If your car starts to sputter or hesitates when you accelerate, take it in for auto repair.

Conclusion on Injection Pump

Direct fuel injection into the combustion chamber is accomplished by injectors. They are supplied by the fuel rail
and via short high-pressure fuel lines. The engine control unit manages the switch valve
integrated into the injector thus opening and closing the injection nozzle. The switch valve
can be controlled either electromagnetically or by a Piezo element.