4903472 4026222 4061851 4928517 injector

What are Cummins ISM QSM M11 Engines and QSM11 Fuel Injectors

Cummins engines have long been synonymous with exceptional performance, reliability, and fuel efficiency. Among their notable lineup, the Cummins QSM11 engine is a powerful and versatile engine known for its performance and reliability in various industries, from transportation to construction and beyond. A key component that contributes to its efficiency is the electronically controlled unit injector (EUI) system used for fuel delivery.

Specifications of the QSM11 Engine.


300-715 hp (224-533 kW)


1160-1750 lb-ft (1573-23733 N•m)

Injector No.

4903472 4061851 4928517 4026222 etc.


In-line, 6-cylinder, 4-stroke diesel


Turbocharged / Aftercooled


10.8L (661 In3)

Bore & Stroke

125*147mm (4.92*5.79 in)


Counterclockwise facing flywheel

Fuel System


EUI System:

The QSM11 engine employs an advanced electronically controlled unit injector system. This system ensures precise fuel delivery to each cylinder, optimizing combustion for enhanced performance and fuel efficiency. The EUI system can adjust injection timing with an accuracy of up to ±1 degree, ensuring optimal fuel combustion.

Injector Design:

The injectors used in the QSM11 engine are designed with durability and precision. These injectors are constructed using high-quality materials capable of withstanding the high pressures involved in fuel delivery. They are engineered to provide precise fuel atomization, with injector hole sizes as small as 120 micrometers, allowing for better fuel-air mixing in the combustion chamber.

Here’s an overview of the injectors in a QSM11 engine:

1). Fuel Delivery: Imagine the engine’s cylinders as small chambers where fuel and air mix and burn to create power. Injectors are like precision nozzles that spray a fine mist of fuel into these chambers. This fuel is crucial for the engine to generate power.

4903472 4026222 4061851 4928517 injector

2). Timing is Key: Injectors operate with perfect timing, syncing with the engine’s movements. They spray fuel at just the right moment in the engine’s cycle to ensure efficient combustion. Think of it like a chef adding ingredients to a recipe at the exact time needed for the best taste.

3). Creating Power: When the fine mist of fuel mixes with air in the cylinder, it ignites, creating a controlled explosion. This explosion generates the force needed to move the engine’s pistons, which, in turn, powers the vehicle or machinery the engine is installed in.

4). Precision Matters: The design of these injectors is precise. They break down the liquid fuel into tiny droplets to ensure even mixing with the air. This precision helps the engine run smoothly and efficiently.

5). Controlled by Electronics: In modern QSM11 engines, computers control these injectors. They adjust the timing and amount of fuel sprayed into each cylinder based on various factors, like how fast the engine is running or how hard it’s working. It’s like having a smart chef that adjusts the recipe in real time for the best results.

6). Built Tough: These injectors are built tough because engines often work in harsh conditions. They can withstand high temperatures and pressures without breaking down.

7). Maintenance and Replacement: Over time, just like any part, injectors may need maintenance or replacement to keep the engine running its best. Proper care ensures the engine continues to perform reliably.


In summary, injectors in a QSM11 engine are like precision nozzles that deliver fuel with perfect timing to create controlled explosions, producing the power needed for the engine to run efficiently and effectively in a wide range of applications.


In this article, we explain how to replace the injector in the QSM11. Please click here.