Cummins PT Fuel Systems - Cummins patented the PT (pressure-time) fuel injection system in 1954.
The PT system relies on injectors to meter and inject the fuel into the cylinder with metering based on a pressure-time principle. The interval determines the time for metering that the metering orifice of the injector stays open. This interval is ascertained and controlled by the engine speed, which determines the rate of camshaft rotation and consequently the injector plunger movement. Fuel pressure gets supplied by a gear-driven positive displacement fuel pump.
Because Cummins engines are all four-cycle, the camshaft gets driven from the crankshaft gear at one-half of engine speed. Consequently, the fuel pump rotates at engine speed. Due to this relationship, additional governing of fuel flow is required in the fuel pump.
Cummins CELECT fuel system, Cummins' first electronically controlled fuel system
The CELECT fuel system is Cummins first electronically controlled unit injection system, released in 1990. Currently used on Cummins M11 engine platform, CELECT is a cam driven system that provides high injection pressure.
Cummins CELECT Injectors provide:
Longer engine life
Improved fuel economy
Better performance, reliability, and durability
Lower emissions
Cummins HPI (BOSCH) fuel system, High pressure injection system (HPI)
The Heavy Duty HPI system is an electronically controlled unit injection system currently used on the Cummins Inc. ISX 15 liter products. This open nozzle system provides higher pressure injection than previously released Cummins systems.
Similar to the Heavy Duty model, the High Horsepower HPI system is an electronically controlled unit injection system. In order to meet a variety of customer needs, the high-horsepower HPI system can be utilized in multiple engine cylinder configurations. This system is used on Cummins Inc. high-horsepower engines ranging from 6 cylinder/19 liter to 18 cylinder/78 liter.
Cummins CAPS fuel system
Beginning in 1998, Cummins introduced the ISC based off the earlier mechanical 8.3 C-series engine. The original ISC engine featured a Cummins Accumulator Pump System (CAPS).
This CAPS pump was a computer controlled injection pump,with individual fuel lines to each injector. In 2003 the HPCR system was introduced.
Cummins Accumulator Pump System (CAPS) fuel injection pump for Cummins 6 cylinder C series engines where used in heavy Duty on-road, agricultural applications and many Motor-home applications.
Cummins common rail fuel system (CCR)
The common rail injection system is used in engine applications previously supported by pump-line-nozzle (PLN) fuel systems for Medium Duty and smaller diesel engines. The Cummins Common Rail fuel pump offers higher injection pressure and requires less power to operate, resulting in improved fuel economy and emissions targets compared to competitors' fuel systems. The CCR pump is used on Cummins Inc. ISL 9 liter and ISC 8 liter engines.
Cummins ultra-high pressure injection system (XPI)
The Cummins HD XPI System is a common rail system that provides the highest injection pressure of any other common rail system. Primarily targeted for mid-range and heavy-duty applications, the XPI system is the result of Cummins market leading technology. The XPI provides industry-leading injection pressure and, as a tailored system, delivers optimal engine performance and improved fuel economy to mid-range applications.
