If you see dark gray clouds coming out of the tailpipe, or find that the diesel engine stalls or has difficulty accelerating, the fuel injectors may need maintenance. Clean, well-functioning injectors are the key to achieving the most efficient performance and mileage from a diesel engine. To treat minor clogs and maintain, an excellent solution may be to add a diesel fuel additive to the tank. However, if you detect more serious clogs, you may need to use a cleaning kit to remove any harmful buildup from the fuel injectors.
Method 1 of 2: Use Diesel Fuel Additives
Step 1. Buy an additive that is compatible with your engine
These fuel additives are inexpensive, easy to use, and keep your engine cleaner. They can help the engine burn fuel more efficiently and prevent buildup around the injectors. You can often notice a difference in diesel engine performance immediately after using a fuel additive.
- You should check the packaging to make sure the additive you buy is for diesel fuel and compatible with your engine.
- If the additive does not indicate that it is for diesel engines, you should check the packaging to see if your engine type or vehicle model is on the list.
- Some popular brands of fuel additives that keep injectors clean are Stanadyne Performance Formula One Shot and Lucas Fuel Treatment. You can find both at your local auto parts store or online.
Step 2. Make sure the engine is off and the fuel tank is almost empty
Before putting any additives in the tank, you need to make sure the engine is not actively burning fuel. Also, you should add additives to a tank that is nearly empty so that the additive can pass through the fuel system at a high enough concentration to clean it.
Keep the engine off and remove the key from the ignition
Step 3. Locate and open the vehicle's fuel tank
Most cars have a fuel tank access cap on the left or right side of the rear of the car, but some trucks and other engines may have it in a different location. Look for a cap that has a fuel pump handle symbol on it and remove it to access the tank.
You will likely have to open a hatch to get to the fuel cap. Also, some vehicles require you to pull a lever near the driver's seat to open the hatch
Step 4. Pour the recommended amount of additive into the fuel tank
The amount of additive you need to add can vary depending on the size of the tank. Engines with larger tanks need more additive. Check the packaging to find the recommended amount for your tank, measure out the correct amount, and pour it inside.
You will likely have to use a funnel to pour the additive into the tank
Some fuel additives (like Stanadyne Performance Formula One Shot) come in containers designed so that you can pour the product directly into the tank, so you don't have to measure it or use a funnel.
Step 5. Fill the tank with fuel, start the engine and let it run for 10 minutes
Once you have poured the additive into the fuel tank, fill it with diesel and start the engine to begin circulating the fuel along with the additive throughout the system. The additive is formulated to maintain fuel injectors and prevent them from accumulating debris that can clog them.
- You can drive the vehicle or just leave it idle for 10 minutes.
- For added convenience, you can add the injector cleaner while working on the fuel pump and then fill the tank with diesel.
Method 2 of 2: Connect a cleaning kit
Step 1. Use a cleaning kit to clean clogged fuel injectors
If your engine stalls, or you notice dark clouds of smoke coming from the tailpipe, then the injectors are likely to have some serious clogs. If this is the case, it is best to use a cleaning kit to remove accumulated debris. Fuel Injector Cleaning Kits are relatively inexpensive and easy to use. In addition, they effectively remove difficult clogs in the injectors.
- Check the packaging or do some research online before purchasing the kit to make sure it is compatible with your engine.
- Check the details of the kit to verify if the engine of your vehicle model is listed as a compatible one (in which it can be used).
- You may need to purchase additional connectors or adapters, so make sure you have all the necessary parts.
Step 2. Make sure the engine is off before working
You will be working on the engine's fuel system, which can be dangerous if the engine is running and actively burning fuel. Make sure the engine is off and remove the keys from the ignition.
- It doesn't matter how much fuel is in the tank.
- Remove the keys from the ignition to prevent the battery from sending power to the engine, which could cause a shock.
Step 3. Remove the cap from the fuel tank
When connecting and operating the cleaning kit, the fuel system will be under more pressure than normal. You can make sure the extra pressure doesn't build up by opening the cap that covers the fuel tank.
If you're working on a car, keep the hatch covering the fuel cap open and remove it
Step 4. Remove the fuel pump fuse to disconnect it
The fuse box is located under the hood inside a plastic cover. Open it and use the diagram to locate the fuel pump fuse. Pull the fuse out of the box.
If your fuse box does not have a diagram, you can refer to your owner's manual to locate the fuse
You may need to use needle nose pliers to remove the fuse.
Step 5. Try to start the engine to make sure the pump is off
It is very important that the pump is disconnected so that the cleaning kit can work in the fuel system. You need to turn the key in the ignition to start the engine and make sure the pump is off. If you try to start, but it is not possible, it means that the injector has disconnected.
You should hear the "click" of the starter button trying to start the engine
Step 6. Connect the injection chute outlet hose to the cleaning kit
This element (which supplies the diesel to the fuel pump) is connected to the injector. Since the pump has been disconnected, you can disconnect the outlet hose and connect it to the kit where it is indicated that it should be connected.
Check the cleaning kit instructions to ensure proper air pressure is flowing into the kit. If there is too much, you can turn the dial to adjust the flow on the cleaning kit
Step 7. Start the engine and let it run for 15 minutes to allow the solvent to run out
Once the kit is connected, you can turn the key in the ignition to start the engine and let the cleaning kit flow the cleaning solvent through the system. Since the pump has been disconnected, the engine will run on the fuel from the cleaning kit. Let the engine run until the solvent runs out and the engine stops.
Avoid driving the vehicle while the solvent is burning to clean the injectors. Leave it idle until the engine shuts down
Step 8. Turn off the battery, disconnect the kit, and reconnect the fuel pump
When the engine stops running because the solvent has run out, remove the key from the ignition to turn off the battery and replace the pump fuse. Then, disconnect the tube from the cleaning kit and reconnect it to the injection chute.
- The engine will start to use the fuel from the tank, instead of the fuel from the cleaning kit. If the tank previously had fuel, you don't need to add more.
- Everything in the engine should be back to the way it was before connecting the cleaning kit.
Step 9. Start the engine and detect any unusual noises
The engine should run smoother after cleaning and nothing should sound out of the ordinary. Give the car or truck a little drive to make sure it's working properly. If you notice a problem, you should take it to a mechanic.