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Cummins 4BT Fuel Injector Pump : OEM 3928602RX

CUMMINS 4BT FUEL INJECTOR PUMP : OEM 3928602RX

Shipping ICON

ORDERS PLACED BEFORE 3PM EST WILL SHIP SAME DAY

WARRANTY ICON

WARRANTY
1M MILES OR 1 YEAR

$1,895.00

CORE CHARGE:

$1,200.00
iCORE DISCLAIMER: The CORE charge is a 30 day hold and will not be processed as long as the CORE is returned within 30 days. If you do not have a CORE or fail to return the CORE within 30 days, the CORE charge hold amount will be processed at that time.

AVAILABILITY IN STOCK
OEM NUMBER3928602RX
PART TYPEFuel Injector Pump
BRANDTamerx Diesel Products
ENGINE MAKECummins
ENGINE TYPE4BT
YEAR
PART NUMBER3928602RM

PRODUCT DESCRIPTION

This is a Remanufactured Tamerx Fuel Injector Pump, Tamerx part number 3928602RM ( OEM Part Number 3928602RX ). 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 4BT, and comes with a One Million Miles or One Year Warranty. For additional warranty info Click Here

OEM NUMBERS

Primary OEM3928602RX
Additional OEM3928602RX

ADDITIONAL DETAILS

CONDITIONRemanufactured
UPC / Barcode00840490539730
WEIGHT18.00 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.


Bring your Cummins 4BT roaring back to life with the Fuel Injector Pump — OEM 3928602RX. Designed for pinpoint fuel delivery and reliable pressure control, this pump keeps your 3.9L engine running clean, efficient, and powerful. Built tough to OEM standards and backed by a one-million-mile or one-year warranty, it’s the dependable choice for smooth starts, sharp throttle response, and long-lasting performance—mile after mile.

PEOPLE ALSO ASKS | BLOG(S)

When your Cummins 4BT engine starts running roughly, losing power, or emitting more smoke than usual, the fuel injector pump should be high on your checklist. The OEM 3928602RX pump is built to deliver precise fuel pressure and timing for the 4BT’s injectors—ensuring efficient combustion and reliable engine behavior.

  • Restores consistent injection timing which helps eliminate misfires, rough idle, or lag during acceleration.

  • Maintains steady fuel pressure so each cylinder gets the right amount of fuel. This results in cleaner combustion and reduces soot and smoke.

  • Helps protect injectors, fuel lines, and emissions components by ensuring fuel is metered cleanly and accurately.

  • Built to OEM specifications—this means direct compatibility, a perfect fit, and reliable durability.

  • Supported with solid warranty coverage and designed for years of dependable operation under daily duty.

Swapping in the OEM 3928602RX injector pump is more than replacing a worn component—it’s restoring proper fuel delivery and system balance to your Cummins 4BT. For clean starts, smoother running, and a healthier engine, choosing genuine OEM parts from Tamerx Diesel Parts makes all the difference.

The fuel injector pump is essential for delivering pressurized fuel into the engine’s combustion chamber at the right time and volume. When this component fails or starts to malfunction, it can lead to poor engine performance, starting issues, and even stalling. Diagnosing a faulty fuel injector pump early can save you from costly repairs and prevent further engine damage.

Ways to Test or Diagnose a Bad Fuel Injector Pump

  • Hard Starting or No Start Condition
    If the engine cranks but doesn’t start, it could be due to inadequate fuel pressure caused by a failing injector pump.

  • Listen for the Pump Noise
    When turning the ignition key to the “on” position (before starting the engine), you should hear the fuel pump prime. Silence could indicate a dead pump or electrical fault.

  • Check Fuel Pressure with a Gauge
    Attach a fuel pressure gauge to the fuel rail or pump test port. Compare the reading to the manufacturer’s specifications. Low or no pressure often signals pump issues.

  • Look for Engine Misfires or Hesitation
    A pump that isn’t supplying enough fuel may cause misfires, rough idling, or hesitation under load.

  • Inspect for Fuel Leaks or Air Intrusion
    Air in the fuel system or leaks near the pump may interfere with fuel delivery, giving symptoms similar to pump failure.

  • Check Diagnostic Trouble Codes (DTCs)
    Use an OBD-II scanner to check for error codes. Codes related to fuel pressure regulation, injector timing, or pump circuit issues may point to a faulty pump.

  • Perform a Flow Test
    Disconnect the fuel return line and run the engine briefly. Measuring the return fuel volume can help assess pump performance.

  • Electrical Inspection
    Test the wiring harness and relay supplying power to the pump. Poor connections or faulty relays can prevent proper operation.

Diagnosing a bad fuel injector pump involves both mechanical and electrical checks. By observing symptoms like low fuel pressure, misfires, or hard starts—and confirming them through testing—you can pinpoint pump issues early. For accurate results, always follow manufacturer-specific diagnostic procedures and consult a trusted technician if you're unsure. Proactive testing helps ensure your fuel system stays in top shape.

Relieve system pressure and shut off power to avoid fuel spray and risk of injury.

Efficiency drops, fuel consumption rises, and exhaust smoke increases due to incomplete combustion.

Prolonged misdelivery of fuel may damage pistons, valves, and exhaust components, and increase maintenance costs.

A whining or knocking sound under load or startup may indicate worn internal gears, bearings, or vanes.

Cummins Fuel Injector Pumps

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