
Cummins QSL, 8.3L Fuel Injector 2003-2012: OEM 5263306RX ( Set of 6 )
CUMMINS QSL, 8.3L FUEL INJECTOR 2003-2012: OEM 5263306RX ( SET OF 6 )

ORDERS PLACED BEFORE 3PM EST WILL SHIP SAME DAY
WARRANTY
1M MILES OR 1 YEAR
PRODUCT DESCRIPTION
This is a Remanufactured Tamerx Fuel Injector, Tamerx part number DE813-SET ( OEM Part Number 5263306RX ). All parts are proudly remanufactured in the U.S.A. to the highest of OEM standards, and improvements are often applied to the original design in the remanufacturing process. This part is primarily made for a Cummins QSL, 8.3L, production years 2003-2012, and comes with a One Million Miles or One Year Warranty. For additional warranty info Click Here
OEM NUMBERS
Primary OEM | 5263306RX |
Additional OEM | 3965750, 4940171, 0445120240, 5263306RX, 87538123 |
ADDITIONAL DETAILS
CONDITION | Remanufactured |
UPC / Barcode | |
WEIGHT | 9.30 LBS |
SHIPPING OPTIONS
Ship Weight : 9.30 LBS
UPS Ground, 2nd Day Air, Next Day Air
SHIPPING POLICY
Tamerx Diesel Products ships via UPS Ground. Next day air shipping can be arranged for a reasonable price of anywhere from $50.00 - $100.00 depending on the weight of the product and your location. We will do everything we can to make sure that you get the service you need. We understand how important it is to receive your order as quickly as possible.
In most cases Tamerx Diesel Products only needs one address, as long as your product is shipping to the same location as your billing information. In order to eliminate credit card fraud, your billing information must match the credit card you provide.
The terms, conditions, and details of our warranty vary from product to product. Specific warranty details can be found below.
Tamerx Diesel Products provides a replacement warranty on all of our parts. The duration and mileage limitations of the warranty vary by product and are specified on the product's detail page/item listing.
Please note that the warranty covers replacement of the part and the cost of shipping the replacement part to you only. It does not cover any shop, labor, towing, or any similar or related costs. This is not a "money back guarantee".
If you experience a problem with your part or it is not functioning properly, the correct warranty procedure is to call us at (510) 257-1777 (8:00 AM - 5:00 PM ET Monday through Friday). Be sure to have your order number and/or other relevant order information ready so we can easily locate your order and resolve your issue as quickly as possible. From that point, we will review with you any troubleshooting steps that may need to be taken and other areas or systems that can be checked to rule out external problems contributing to your part's issue. If a replacement is determined to be necessary, we will then arrange for your replacement part to ship out ASAP and issue any necessary return shipping labels and/or documents.
As is the case for the majority of the diesel products sold on Tamerx Diesel Products, your part's warranty is active as soon as you install it. In some other cases, warranty activation is contingent upon you sending us your core (i.e., your old part). Tamerx Diesel Products will provide you a return shipping label for parts that have a warranty with a core return condition. When we have received your core return, the part's warranty coverage begins. We reserve the right to void the product warranty if your core is not received within the allotted time, or if it isn't received at all. If the warranty for the diesel part you are purchasing has a core return requirement, it will be clearly noted on the product detail page/item listing.
What is a Core Charge?
A core charge (also called "core deposit") is similar to the deposit you might pay for a can or bottle of soda and is a standard requirement in the auto parts industry. For example, in many states, to promote recycling, you pay a deposit when you purchase a can of soda and receive your deposit back when you return the empty can. Many automotive parts have a core charge, or core price, that works in essentially the same way as a soda can deposit.
30 Day Core Charge Hold
You authorize Tamerx Diesel Products, to hold your credit card for the specified core charge amount and that you agree to return your core with 30 days of receiving the purchased part. When we have received your core return, the hold is released and the core charge payment is canceled.
The customer, or parts buyer, is responsible for any shipping costs associated with core returns unless otherwise specified in the product listing/detail page. Tamerx Diesel Products offers prepaid UPS shipping labels (SKU numbers UPS-CR1 and UPS-CR2) for use in returning your core that are available for purchase on our website during your shopping/order process.
The shipping label you will need to use for the core return is dependent upon what part you are purchasing. UPS-CR1 is good for cores weighing up to 20 pounds. UPS-CR2 is appropriate for shipping cores weighing 21 pounds or more. You must include enough information with the core return that clearly identifies it as a.) a Core Return, and b.) contains enough information we can use to clearly associate the core return with your order. Including a copy of the invoice or packing slip that came with the original shipment, clearly marked "Core Return", is ideal. Alternately, you can include a note marked as "Core Return" that includes your order number, full name and address, and phone number or other contact information. Failure to include this information with your returned core will most likely delay any due core credit being issued and/or delay any applicable warranty activation. Core returns need to be for the exact part purchased and cannot be damaged. Substituting another part in place of the part you have purchased is not acceptable.
All fluids must be drained.
If you have purchased a set or a parts package, you will need to return cores for all components of the set. For example, if you have purchaed a high pressure oil pump with an IPR valve, you will need to return both HPOP and IPR valve cores to receive proper credit. If you have purchased an EGR cooler/EGR valve package, your core return must consist of an EGR cooler core and an EGR valve core, or core credit will not be given.
Core Charges are often mandated by state legislature, and, as such, the actual core charge and taxes on the charge may vary depending on the state in which you buy your part. The Tamerx Diesel Products core charge presented to you online today with your item is representative of the most common core charge.
Designed to meet the demands of heavy-duty engines, the Cummins QSL and 8.3L Fuel Injector Set (OEM 5263306RX) for 2003–2012 includes six precision-built injectors that deliver accurate fuel flow for efficient combustion. Engineered specifically for the QSL and 8.3L Cummins platforms, these injectors help ensure consistent engine working conditions, smooth operation, and long-term reliability. Each unit is rigorously tested and inspected to meet strict industry and quality standards, making this set a trusted replacement solution. Ideal for commercial and industrial applications, it supports optimal engine functionality in demanding conditions.
FITMENT CHART
YEAR | MAKE | ENGINE(S) | ||||
---|---|---|---|---|---|---|
2003 | Cummins | QSL | 8.3L | |||
2004 | Cummins | QSL | 8.3L | |||
2005 | Cummins | QSL | 8.3L | |||
2006 | Cummins | QSL | 8.3L | |||
2007 | Cummins | QSL | 8.3L | |||
2008 | Cummins | QSL | 8.3L | |||
2009 | Cummins | QSL | 8.3L | |||
2010 | Cummins | QSL | 8.3L | |||
2011 | Cummins | QSL | 8.3L | |||
2012 | Cummins | QSL | 8.3L |
PEOPLE ALSO ASKS | BLOG(S)
The Cummins QSL, 8.3L Fuel Injector is a critical part of the fuel delivery system in heavy-duty diesel engines, ensuring efficient combustion and proper engine function. Designed for models from 2003 to 2012, these injectors play a vital role in providing precise amounts of fuel to the engine cylinders.
Key features of the Cummins QSL 8.3L Fuel Injector include:
- OEM 5263306RX
- This refers to the specific original equipment manufacturer number, ensuring compatibility with Cummins engines.
- Accurate Fuel Delivery
- Ensures that the right amount of fuel is injected into each cylinder, optimizing combustion.
- Improved Fuel Efficiency
- The injector's design helps maximize fuel efficiency, leading to lower fuel consumption.
- Durability
- Made with high-quality materials to withstand the demands of heavy-duty engines.
By using the correct injectors, you maintain optimal engine function and prevent issues such as fuel misfiring or inefficient combustion. A well-functioning fuel injector set ensures that your Cummins QSL 8.3L engine runs smoothly and effectively, providing reliable power and efficiency over time.
The lifespan of a fuel injector depends on several key factors, which can affect its overall functionality and longevity. Understanding these elements can help you maintain your vehicle and prevent injector failure.
One major factor is fuel quality. Contaminated or low-grade fuel can lead to the buildup of dirt and deposits, which will shorten the injector’s lifespan. Regular use of clean, high-quality fuel can reduce the risk of clogging.
Driving habits also play a role. Frequent short trips, excessive idling, and aggressive driving can place unnecessary strain on the fuel system, including the injectors.
Other factors include:
- Maintenance schedule
- Regular filter replacements and injector cleanings help prevent damage.
- Fuel system pressure
- Ensuring the fuel system pressure is within the recommended range is crucial.
- Environmental conditions
- Extreme temperatures or exposure to moisture can contribute to corrosion and wear.
Finally, the age and type of engine can affect how long fuel injectors last. Older engines may experience more wear and tear, while modern engines are designed to run more efficiently with injectors that can last longer. Keeping these factors in mind will help prolong the life of your fuel injectors.
Yes, excessive return flow or internal leakage in a bad injector can lead to low rail pressure and reduced engine efficiency.
Over-fueling can cause black smoke, poor idle, excessive fuel consumption, and potential piston damage.
Yes, a malfunctioning injector can disrupt combustion in a single cylinder, which may feel like a complete engine misfire under load.
Yes, water, debris, or microbial growth in diesel can erode internal components and clog precision passages.