The LB7 Diesel Fuel Injector was the first in a long line of Duramax engines that General Motors built in collaboration with Isuzu that would go on to become household names for diesel vehicle owners. It changed the game in several ways, perhaps the biggest of which is by adopting the CRI common rail direct injection system offering multiple injections per power stroke that helps make diesel engines quieter, reduce emissions, increase power, and be more fuel efficient. Besides this, the Duramax’s compact engineering and lightweight yet durable parts made it an extremely reliable engine that only required basic maintenance and lasted several hundred thousand miles.

However, as with all good things, the one prominent issue with the LB7 is that its injectors are vulnerable to failure. The failure generally happens either because the injectors internal components become worn out and eventually leak, or the injector cracks, leading to air and fuel issues. This makes it very important to pick a reliable replacement injector for your LB7, because a faulty, outdated, or subpar replacement could demand additional expenses worth hundreds of dollars. If you’re suffering from this issue, Dieselogic makes dependable, remanufactured/manufactured again injectors using original equipment manufactured (OEM) Bosch cores. Read ahead to find out more about them and why they might be your best option if you’re looking to replace your injectors.


How long do LB7 injectors last?


Considering that the LB7’s injector problems have been well-documented, GM responded by extending its original injector warranty to 7 years or 200,000 miles. However, a replacement injector’s lifespan is unpredictable. They may give you just 70,000 miles or even upwards of 200,000. However, on average, a replacement injector will last you between 80,000 to 100,000 miles.

The lifespan of an injector can depend on several factors. For one, the specific vehicle you’re using the LB7 for can impact how long the injector lasts. Amongst other factors is how often and well maintained the injectors and engine are. Basic filtration maintenance and fuel grade/quality can significantly increase the lifespan of your injectors, especially since the LB7 ones are particularly prone to internal clogging and cracking.

Third, who you buy the injectors from and the method they followed to remanufacture/manufacture again or refurbish the injectors is extremely important. Replacing injectors is expensive, not to mention the amount of labor is upwards of 14 hours for removing and reinstalling, which makes the choice of replacement an even more critical consideration.

Unfortunately, many people choose to compromise and opt for a cheap injector, only for it to break down in a couple of months and cost more in the long run. As such, it’s essential that you buy your injectors from a trustworthy brand with a reputation for making reliable injectors that will give you sufficient value for your money.


How to Rebuild LB7 Injectors?


Considering the propensity of an LB7 diesel fuel injector to fail, it may be best to leave the injector rebuilding to professionals. However, if you think you have enough experience and are confident in your abilities, here is how you could rebuild them yourself at home and save on costs. However, be warned that even seasoned experienced professionals with all the proper tools and equipment make mistakes from time to time.

The first step is to simply take the injector apart once you’ve removed it from the engine. The injector has tiny and precise parts, the nozzle, the cap, and the body to name a few. Remove the copper washer on the nozzle and unscrew it until it comes off. The body contains its own washer, a spring, and other components that might slide out once you remove the nozzle. After you take out the nozzle, you’ll see a spring with a small disc at the top of the body. Remove the disc and spring to open up the body of the injector.

Clean out all the dirt, grime, and dust inside using denatured alcohol and a small brass brush. Pressurized air cans are also handy for getting all the stubborn carbon deposits and bits out. Once you’re done, use paper towels to rub everything and make sure it’s dry.
While re-assembling, you’ll need to replace the nozzle and cap. Put back all the small parts the way you saw them come out when taking the injector apart. Use a wrench to tighten the new cap and nozzle on and torque to the proper OEM specification.
Another option you might consider is getting a fuel injector repair kit. These kits are great for fixing minor issues such as general wear and tear or leaks, but will not address larger and more complex issues.

Also, keep in mind that the likelihood of a DIY injector rebuild failing is quite high, and the general consensus seems to be that it should not be attempted unless you have specific expertise in this area. If you see excessive smoke upon starting your vehicle, hear odd sounds, or observe any other signs that something is off, the rebuild might not have worked out. We at Dieselogic offer our own remanufactured/manufactured again LB7 injector to save you the hassle of rebuilding things yourself. We’ll discuss this further below.


How Do I Get More Power Out of My LB7/How to Get Better fuel Mileage With LB7?


There are several ways to make sure you get more mileage out of your LB7 Duramax engine. One way is to follow some general practices that reduce diesel fuel expenditure when using your vehicle.

First, ensure that your tire pressure is adequate and within properly manufactured recommendations. You lose about 1% of fuel efficiency for every 10 PSI below the appropriate amount. Second, don’t keep your vehicle idling for too long since it burns a lot of fuel over time. Third, don’t accelerate excessively or change gears too quickly because doing so requires additional fuel combustion that reduces mileage. Instead, try to maintain a steady pace as far as possible. Fourth, make more efficient use of your AC. When you’re driving in the city area, keep your windows down instead of using the AC as far as you can. However, when you’re on the highway, it’s better to keep the windows up to reduce the drag on your vehicle so as to increase your aerodynamics. Lastly, maintain your vehicle regularly and thoroughly to ensure all its parts are running smoothly and that it is in pristine condition for best mileage.

Besides these best practices, vehicle owners typically make small adjustments to the engine or vehicle to further reduce fuel consumption. This includes removing the tailgate, using a bed cover, installing new fuel filters, deleting the (EGR) exhaust gas recirculation valve, etc. However, not all of these methods are as effective as you’ll see some claim and can even reduce your efficiency in some instances. Do some research about the effectiveness of each specific measure and decide whether it’s the best course of action for you.


Consider Dieselogic’s LB7 Diesel Fuel Injector


If you’re in the market for an LB7 diesel fuel injector and have decided to not rebuild it yourself, you might be interested in Dieselogic’s offerings. Our fuel injectors are 100% flow tested and have Electro Discharge Machine drilled spray holes for spray plume uniformity and flow balance. They are also equipped with Abrasive Flow Machining (AFM) and premium nozzles to keep up with the needs of a modern diesel engine.

Our injectors also use OEM Bosch cores and are remanufactured with up-to-date OEM specifications. Even though ours are ‘manufactured again’ instead of brand new, the former is completely indistinguishable from a new injector. Our injectors have been rigorously tested to ensure peak performance and all replaced parts are of premium quality. Every part is disassembled and thoroughly checked for defects, extensive damage, or wear and tear. Those that do not meet the OEM Bosch performance specifications are tossed out and replaced. Besides this, buying manufactured again products also helps reduce waste and pollution in the environment.

Dieselogic has been a part of the diesel injection fuel system remanufacturing industry for over 55 years now, and our experience with handling LB7 diesel fuel injectors is unmatched. Our prices are also among the best you’ll see because we cut out the middle man. If you see a price lower than ours, call us to discuss price matching immediately. All of our work is done in the USA, including our in-house customer service representatives that will go above and beyond to ensure that you have the most comfortable experience with us.

If you’re still on the fence about our LB7 diesel fuel injector, call us so that we can have a productive discussion about your needs, specific application, and how we at Dieselogic can best help you and address your concerns.




The LB7 Duramax engine was a trailblazer with its common rail direct injection system, and its top competitors soon jumped on this bandwagon. Despite its many benefits, such as reduced emissions, quieter engines, and better efficiency, one major issue with the LB7 is that its fuel injectors are prone to failing. This is either due to internal clogs or leaks and cracks that result in flow issues. The quality of replacements on the market can vary widely, and a good replacement injector could give you tens of thousands of more miles than a cheaper option. Getting a faulty injector or trying to rebuild one yourself can cause more problems than it fixes, making it advisable for you to leave this one to seasoned professionals. Dieselogic has over five decades of experience in the remanufacturing market of this sector, and our injectors are easily among the best replacements you’ll find. We are actually better than new (OEM) because our injectors meet or exceed OEM specs and standards while being more inexpensive than OEM. To find out more, call us today!