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Show your support with a Thoroughbred Diesel t-shirt, sweatshirt, or sticker decal.
Thoroughbred Sku #: DELEX638665-CRE
$636.70
Terms & Conditions for Cores
Many stock replacement parts such as turbos, injectors, injection pumps, and high pressure oil pumps have a core charge that is associated with the new replacement part. You must return the old part to receive a refund on the core charge.
If you plan on returning your core you have two options.
Thoroughbred Diesel offers defer the upfront core charge when purchasing via credit card payment.
OPTION 1: You can accept the core charge, which means you will be charged for the part AND the core at time of purchase. You still have the option to send it back, and if you do, the core will be refunded back on the card used, presuming the core meets core criteria and the core is returned within 30 days from the time your order is received. If you return your core after 30 days you may refer to the Core Charge Timeline below as to how you will be refunded.
Core Charge Timeline
OPTION 2: You can defer the core charge. If you defer, you will not be charged for the core at the time of purchase. You will have 21 days from the time your order is received to send the core back. If the core is not received within the 21 days, your credit card will be charged for the core amount on your order. If you return your core after 21 days, you may refer to the Core Charge Timeline below as to how you will be refunded. When Core deferral (Pay Core Charge Later) is limited to payment by credit card only. ***When using PayPal or Affirm as your method of payment “Core Deferral (Pay Core Charge Later)” is not available. The core must be paid at time of purchase. ***
Core Return Procedure
Product Name: Delphi Cummins ISX Diesel Remanufactured Fuel Injector Manufacturer: Delphi Manufacturer Part #: EX638665 Thoroughbred Diesel Part #: DELEX638665
Restore proper fuel delivery and engine performance with the Delphi EX638665 Remanufactured Fuel Injector for Cummins ISX diesel engines. Built as a direct-fit replacement, this High Pressure Injection (HPI) injector is engineered to deliver precise fuel atomization, stable combustion, and consistent power output under demanding operating conditions. It helps correct common issues such as rough idle, hard starting, excessive smoke, poor throttle response, and reduced fuel economy. Delphi states each ISX injector is tested for leaks, injection pressure, fuel delivery, and timing, with new matched nozzles and replacement critical wear components for dependable long-term service.
OE Numbers 148-075-8665, 1480758665, 209984X, 4076902, 4088665, 4088665NX, 4088665PX, 4088665R, 4088665RX, 8520, DCI4088665R, DELEX638665, EX638665, FS4088665RX, MCBR-MCB4088665, MCBRMCB4088665, R-4088665, R-MCB4088665, R4088665, RMCB4088665, TDM4088665PX
Delphi Features: