Why Not to Rebuild Your Diesel Engine Fuel Injectors

Do your fuel injectors need a rebuild? Have you thought about just doing it yourself? Master Diesel Mechanic Mike Schrems discussed with us why you might not want to tackle this yourself. Read on to find out why!



As you probably know, fuel injectors literally inject fuel into your cylinders during combustion. There are different types of injectors, depending on your engine, that operate differently, but the end result is the same. 

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Your injector is a highly precise device that measures and injects fuel into the combustion chamber in your diesel engine. Because it is such a highly machined component in the engine, it isn't recommended to take this task on at home. It needs to be done in a well-established, environment-controlled clean room.

These clean rooms are almost as sterile as an operating room in a hospital, and the temperature of the room and air cleanliness are key components to maintaining this environment. That's why when you visit one of these injector or fuel pump rebuilding sites, you'll see warnings and cautions to stay clear of the rooms. They don't want to introduce foreign materials that could be airborneyou could do this even by just walking through the room. If you walk something in on the floor, it could get dried out and suspended in the air as they're trying to calibrate these precise components for your diesel engine. 



In addition to the need for cleanliness when working with injectors, there's also the added difficulty of the complicated nature of the components. 


There is a metered amount of fuel injected into the combustion chamber through the orifices. These orifices are located on the nozzle end of the injector. They're put in at a certain angle. In other words, there is a degree of how the fuel is angled into the combustion chamber. It could prove difficult to recreate this precise angle in your garage at home.


Similarly, some of the pistons have a bowl designed into it.  Fuel enters into that cup or bowl at the top of the piston at a certain angle for efficiency, to reduce the smoke, and its burning capability, or its ability to produce powerstroke. Again, the required precision could prove difficult.

Along with complicated components come chances for failure. Learn some common signs your injectors might be failing!


If you're still thinking about rebuilding your own injectors, you should realize that it will probably end up costing you more.

Say for instance you want to replace the cups on it. You might be able to get the cups for the injector, put a new cup in it, and think, "Well, I'm good, I restored the original angle for fuel injection and it reduced the orifice size back to its original state." And while that might be true, it still has to be metered and the metering will change.

To accomplish this, there's an orifice under the screens. That orifice is selected so that it measures the correct amount of fuel to be injected into the combustion chamber. The necessary components to do the job right would end up costing you quite a bit of money.


In the end, we don't recommend trying this job at home. You'd be better off having a reputable supplier or repair facility doing it for you, to ensure your injectors will be operating at their best!


Want to know more about injectors and the ones we offer? We have certified techs on staff to help answer your questions! Call us today at 844-304-7688. Or request a quote online!


Edited August 16, 2019