
Cummins 5.9L Fuel Injector Pump 2003-2006: OEM 3963949
CUMMINS 5.9L FUEL INJECTOR PUMP 2003-2006: OEM 3963949

ORDERS PLACED BEFORE 3PM EST WILL SHIP SAME DAY
WARRANTY
1M MILES OR 1 YEAR
PRODUCT DESCRIPTION
This is a Remanufactured Tamerx Fuel Injector Pump, Tamerx part number 3963949RM ( OEM Part Number 3963949 ). 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 5.9L, production years 2003-2006, and comes with a One Million Miles or One Year Warranty. For additional warranty info Click Here
Additional Notes: V6R962-5
OEM NUMBERS
Primary OEM | 3963949 |
Additional OEM | 0 460 426 373, 3963949 |
ADDITIONAL DETAILS
CONDITION | Remanufactured |
UPC / Barcode | |
WEIGHT | 18.00 LBS |
SHIPPING OPTIONS
Ship Weight : 18.00 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.
Restore precise fuel delivery and dependable performance to your 2003–2006 Cummins 5.9L engine with this OEM 3963949 Fuel Injector Pump. Built to handle the demands of heavy-duty use, this pump ensures consistent pressure, smooth combustion, and optimal engine efficiency. It's the ideal solution for keeping your diesel engine running strong, whether you're towing, hauling, or working hard on the job site.
FITMENT CHART
YEAR | MAKE | ENGINE(S) | ||||
---|---|---|---|---|---|---|
2003 | Cummins | 5.9L | ||||
2004 | Cummins | 5.9L | ||||
2005 | Cummins | 5.9L | ||||
2006 | Cummins | 5.9L |
PEOPLE ALSO ASKS | BLOG(S)
The Cummins 5.9L Fuel Injector Pump, specifically OEM 3963949, is a crucial part of your engine's fuel delivery system. It plays a vital role in ensuring the right amount of fuel is delivered to the engine cylinders, allowing for efficient combustion.
This fuel injector pump is made up of several key components:
- Pump Housing
- The main structure that houses the internal components and keeps the fuel pressurized.
- Plunger and Barrel
- These work together to pressurize the fuel before it is injected into the engine.
- Delivery Valves
- Control the amount of fuel that enters each cylinder.
- Timing Mechanism
- Ensures the fuel is injected at the correct time for optimal engine operation.
- Camshaft
- Drives the plunger up and down, creating the necessary pressure for fuel injection.
Each of these components works in unison to deliver fuel accurately and efficiently to your engine. Regular inspection and maintenance of the fuel injector pump and its components are essential to avoid any potential issues that could disrupt your engine's operation. For high-quality replacement parts, consider the OEM 3963949 injector pump for your Cummins 5.9L engine.
A faulty fuel injector pump can cause a range of issues in your diesel engine. Recognizing the signs early can help prevent more severe problems down the line.
One of the first signs to watch for is difficulty starting the engine. If the pump is failing, it may struggle to deliver the right amount of fuel, leading to extended cranking times or the engine not starting at all.
Another common sign is a loss of power during acceleration. A bad fuel injector pump can cause the engine to struggle when extra power is needed, such as when going uphill or towing.
Here are some additional symptoms to look out for:
- Unusual engine noise, particularly knocking sounds
- Poor fuel efficiency
- Excessive exhaust smoke
- Rough idling or stalling
If you notice any of these signs, it's essential to address the issue promptly. Replacing the fuel injector pump can restore proper engine function and prevent further damage.
Contamination can score internal surfaces, block passages, and cause wear to the pumping elements and control valves.
It should be inspected at major service intervals or immediately if drivability issues or fault codes are present.
Effective filtration prevents contaminants from damaging internal pump components and ensures consistent pressure.
Common tests include fuel flow rate, pressure output, control signal response, and internal leak assessments.