Duramax Fuel Injectors

Which Duramax injectors do I need?

Duramax injectors are specific to the engine generation. An LB7 injector will not work in an LMM. Match your model year first, then decide whether you need a full set or a single.

Not sure which generation you have, or whether it is the injectors? See the Duramax injector guide by generation.

All in stock. LB7 through LMM singles and sets are Bosch Authorized Remanufactured, rebuilt by Valley Fuel Injection & Turbo, a Bosch Authorized Service Dealer. The LML injector is a Genuine Bosch factory reman.

LB7 injectors sit under the valve covers, which is why that job costs more in labor than the parts. Worth knowing before you start.

Test before you buy eight

The most expensive mistake on a Duramax is replacing all eight injectors when two have failed. We bench-test injectors and give you the actual flow and return numbers per injector, so you replace what is bad and keep what is good. On a set of eight at $2,600, testing pays for itself the first time it saves you six injectors.

See common rail injector testing for how that works, or ship them in through the mail-in service.

Symptoms that point at injectors

• Hard starting, especially hot. Injectors leaking down bleed rail pressure between starts.
• Rough idle or a miss that smooths out under load. Classic single-injector failure.
• White smoke at idle that clears as it warms: unburned fuel from an injector not atomizing.
• Fuel in the oil. On LB7s especially, an injector leaking internally dumps fuel past the rings. Check the oil level and smell it.
• Knock or rattle under load. Over-fuelling on one cylinder.

Return-flow testing on the truck narrows it to a cylinder before anything comes apart. That is a phone call away: (530) 668-0818.

Why injectors fail on these engines

Fuel quality and water are the two biggest killers. The tolerances inside a common-rail injector are measured in microns; water and particulate erode the nozzle and the control valve, and once flow goes out of spec the ECM cannot compensate. A plugged fuel filter or a failing lift pump accelerates it. Replacing injectors without fixing the fuel supply gets you a repeat failure. Check the filter interval and the water separator before you spend $2,600.

Core charge, warranty and shipping

A refundable core charge is added at checkout. Send the old injectors back within 30 days and the core is refunded, provided they are rebuildable. A prepaid return label is included. See the exchange program.

Remanufactured injectors carry 12 months, unlimited mileage against defects in materials and workmanship, with 30 days on electrical parts. Full warranty terms. We ship nationwide from Woodland, California; orders process in 1–2 business days. Shipping policy.

Common questions

Should I replace all eight even if only one failed? If the truck has high miles and the injectors are original, replacing the set makes sense. They wear together. If it is a low-mile truck with one bad injector, test first.

Do these need to be programmed? LBZ and later use injector trim codes. Have the codes ready when you install, or the truck will run rough even with good injectors.

Do you work on Cummins and Power Stroke too? Yes: Cummins injectors and Ford Power Stroke.

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