Today’s topic isn’t for newbies but is quite an important task to keep your engine in optimum performance. So if you have limited knowledge about engine’s particularly with regards to diesel fuel injectors, then this post will educate you a lot!
And yes, both diesel and petrol fuel injectors basically gives the same function – to inject fuel to the combustion chamber. But this post is going to be specifically focused on diesel fuel injectors. Because you know, my cars are all diesel fed up machines!
So first, let me share to you a simple background about fuel injectors.
What are Fuel Injectors?
As mentioned above, fuel injector is a part of the engine’s fuel system that is responsible for spraying (or injecting) fuel to the engine’s combustion cylinders. It will then mix with air which helps power the engine.
They are situated in the intake manifold in both diesel and petrol engines. The most popular type in diesel cars is called Common Rail Direct Injection system or abbreviated as CRDI.
Fuel injection is the modern technology when it comes to internal combustion engines, as it uses an injector to spray small amounts of fuel through its tiny nozzle. This nozzle sprays the fuel as mist, instead of a strong jet stream.
When the throttle valve opens, the fuel injector sprays a mist of fuel to mix with air that will create powerful combustion which keeps your engine running.
What Happens When Fuel Injectors Fail?
As an integral part of your car’s fuel system, a bad fuel injector will cause your engine to have a rough idle, and most likely will stall.
This is because it can’t deliver a steady and constant stream of fuel flow to your car’s combustion chamber during power stroke, which interrupts the proper mixture of air-to-fuel ratio.
A failing or bad fuel injector may inject too much or too little fuel into your engine’s cylinders leading to rough idle.
But that is only the tip of the iceberg. Here are some of the symptoms of bad fuel injectors:
- Engine misfiring (delayed throttle response)
- Check engine light
- Fuel leaks into the engine leading to high fuel consumption
So Why Fuel Injectors Go Bad?
Like many causes of engine wear and breakdown, fuel injectors fail is also because of common issues like rusting, clog due to debris and dust particles and many others.
These dirt particles find their way into the injectors and overtime, they accumulate and plug up the nozzle, armature or even damages the needle of the nozzle which prevents it from injecting proper amount of fuel.
So it is important to do everything you can to help prevent these debris from damaging your injectors (and also your car’s entire fuel system) and keeping them clean as longer as possible.
The question is, how?
How does Diesel Fuel Injector Relearn Work?
There are several ways to fix a failing or bad diesel fuel injector. And the most common way is to outright clean the injectors yourself.
And of course, this way is not for everyone as most of us are not mechanics. But I will make a video soon on how you can DIY a fuel injector cleaning task in a diesel engine. So stick around in my channel so you won’t miss a beat!
Okay, again if you don’t know how to remove your engine’s fuel injectors, then you won’t be able to clean it yourself and chances are, you will still depend on your mechanic to do this task for you.
But that’s okay because you really need to perform injector cleaning first (or buy a new one) before you do the next step.
And that step is what they call relearning or reprogramming, which is done using a high end automotive scanner to communicate with your car’s computer box.
This will help your stock diesel fuel injectors to return to its “stock” performance.
So how does diesel engine relearn work?
After you reconditioned (cleaned) your fuel injectors, of course you need to reinstall them to your engine according to their cylinders.
You also need to do injector relearn if you have had the intake manifold off for cleaning (decarbonizing), which is a requirement in most engine maintenance tasks.
An injector relearn service should also be done after the valve clearances have been adjusted. All these tasks should be followed by injector programming to keep your car idling smoothly.
First off, you need to get your car up to operating temperatures, otherwise the reprogramming procedure cannot be executed. So drive your car for at least 15 minutes.
Then you will need a scanner to “relearn” or reprogram your diesel fuel injectors and hook it up to your car’s OBD port. Now select the car you are working on, as similar to most types of scan procedures.
Take note that the engine must be running when performing a relearn test.
When the menu pops up, select “learning” or “Programming” (depends on the scan tool you have). After that, small injector quantity will pop up and simply select that menu.
The next window will ask you if you want to perform or execute that, simply press ok.
Your screen will show Executing or Learning, or Programming, depending on the scan tool you have. While in this procedure, you will notice some changes on the way your engine behaves and sound. Your scan tool will show live information on its screen.
This step will take at least 5 minutes.
Lastly, your scanner will say “complete” or executed depending on your scan tool. You may now disconnect the scanner and go for a road test.
You just completed a successful diesel injector relearn!
Summary
That’s how simple it is to relearn your diesel fuel injectors. Don’t worry, I will do real time injector programming for you guys in the future. So as I said, stick to my channel so you won’t miss that tutorial video!
Here is a glimpse of how to relearn a fuel injector of a MonteroSport.
Image Credits:
WikiPedia User: Panoha
https://commons.wikimedia.org/wiki/User:Panoha
