How to Rebuild Lb7 Injectors: Step-by-Step Instruction

By Samiul Alan - June 22, 2021

how to rebuild Lb7 injectors

An injector is a device that injects liquid fuel into an internal combustion engine, mostly automotive engines. Lb7 is an automotive engine fuel injector.

It's one of the best fuel injectors. Today in this discussion, we will tell you how to rebuild Lb7 injectors.

Lb7 injectors are not very strong, and famously unstable. So, people have to replace them very often. But not for those types of people, who are interested in rebuilding things instead of buying new ones. Now, we will give you some step-by-step instructions on how to rebuild Lb7 injectors.

But before that, first, let's talk about the reasons why injections might fail.

Reasons for Lb7 injections failures

1. Over torqued injection halves

This is a common reason for leaks in the fuel system. Because of this fuel travels to the crankcase and causes many problems.

2. Fuel System Contamination

Poor maintenance will cause the fuel system to fill with water, dust, and other contaminants. They also cause erosion.

3. Low Lubricity

It means the parts of the injector are worn at a faster rate than usual. As a result, it can lead to damage.

4. Old Lb7 injections

Very old Lb7 injections have a design that causes them to wear out faster than new injections. But after 2007 injections have improved and solved this problem.

How to diagnose Lb7 injector failure

There are a few ways to diagnose if your Lb7 injector has failed or not. Here are them.

1. Use your nose

If your vehicle gives a smell of unburned fuel, then it's an indication that your Lb7 injector might be failing.

2. Check the crankcase

Check your crankcase for fuel. If there is any then you're facing leaks in your Lb7 injector.

3. Check balance rate

It's a simple process. If any of your displayed balance rates go beyond 3 mm3 then you probably have a failure in the injector.

How to rebuild LB7 injections?

After a few necessary discussions, here is the part of what you really came here for. To rebuild your busted LB7 injector, you must follow a few simple steps. Here's how to do it:

LB7 injection parts
LB7 injection parts

Step 1: Take it apart

The injector has 3 parts that you must keep in mind while trying to rebuild it. The cap, injector body, and the nozzle. There is a spring inside of the body part.

Take a wrench and rotate the cap to open it. Now the nozzle is separated from the body. That's the part we are trying to replace. Also, take out the spring.

Step 2: Clean the injector parts

If your diesel injector needs rebuilding then it's possible that it's been in use for quite some time. So, there should be some dust and grime inside. First, you need to clean that. Use pressurized air to clean it.

Step 3: Reassemble the parts

Take all the parts which you have separated earlier. Then assemble them as they were before. But this time you will replace the old cap and nozzle with new ones. Use a wrench in order to tighten the cap.

And that's all, you have successfully rebuilt your LB7 injector.

How to prevent the injector from failure?

By doing a few simple things you can allow your injections to last longer. This helps you to avoid the hassle of rebuilding your injections.

Always keep your fuel system clean. It will help you to decrease dust and grime build-up in your injections. It will make them last longer.

Use an injector cleaner. Fuel additives are not recommended. But it's good to use injector cleaners from time to time to make sure your LB7 injections are in the best condition.

Avoid fueling from unreliable sources.

Is it worth rebuilding?

For many people, it would be worth it to feel the thrill of fixing something instead of opting for the easier option of ordering it. Which is enough to justify rebuilding the injections.

But from an economic and technical point of view, I have to say no. The injections are a very delicate part of the engine. Fixing it in an unsuitable environment may allow contaminants to enter inside of it. So, you might have to rebuild it again pretty soon.

On the other hand, there is a matter of cost. Buying the proper components, again and again, will cost enough to not justify rebuilding the injections. It also wastes your precious time.


The bottom line is if rebuilding doesn't justify then buy a new one. But it's not our decision to make if it's worth it or not. You are the one who will decide that it's worth it or not in the end.

Lastly, all we want to say is, thank you for the time you have given us by reading this guide. We hope that the instructions have helped you out to rebuild your Lb7 injections.