Ameer Randolph
Running out of diesel can be a costly mistake. If you run out of fuel, your vehicle will shut down and will not restart until the air that has been sucked into the system is removed. This is called bleeding the fuel system, and it can take several hours to complete. While it is not likely to hurt the engine, the fuel pump might get damaged, and you might need to replace it. The best course of action is to prevent this from happening by keeping an eye on the fuel-level gauge and refuelling when necessary.
Explore related products
What You'll Learn
Restarting the engine
Restarting a diesel engine that has run out of fuel can be a complicated, time-consuming, and costly process. Firstly, do not attempt to start the engine without fuel, as injectors and other parts could be damaged due to a lack of lubrication.
If your vehicle has run out of fuel, the first step is to add more fuel to the tank. Typically, adding 4-5 gallons (15-19 litres) of diesel is enough to restart the engine. However, if your vehicle is on a steep grade, more than 5 gallons (19 litres) may be required.
Next, you must purge any trapped air from the system before restarting the engine. This process is known as "bleeding" the fuel system and can be done by turning the ignition on for 30 seconds and then turning it off. Repeat this process six times in a row. Any remaining air in the system will be purged when the engine starts.
Once you have purged the air from the system, you can attempt to start the engine. Turn the ignition to the "Run" position for 30 seconds, but do not start the engine. This allows the pump to prime the system. Then, turn the ignition off and crank the engine for 15 seconds. If the engine does not start, repeat the previous steps until it starts. If the engine starts but immediately stalls, wait for one minute before making another attempt.
Finally, once the engine starts, allow it to idle for several minutes and check for any leaks before driving. It is important to note that the engine may run rough or produce white smoke if there is still air remaining in the fuel system. This is normal and should stop after a short period. However, if the engine continues to run rough, have your vehicle checked as soon as possible.
Understanding Diesel Fuel Injection Systems
You may want to see also
Explore related products
Bleeding the fuel system
For older diesel engines, bleeding the fuel system can be a challenging task. One must locate the bleeder screw (which is actually a bolt) typically located on the fuel filter housing. It can also be a Schrader valve in the line. Loosen the bleeder (or the union nuts) a few turns with a wrench, but do not completely remove it. You will need a bottle or another receptacle to collect the primed diesel and some rags to clean up.
Newer diesel engines, from around the year 2000 onwards, are more self-serving when it comes to the priming process. After adding fresh diesel, the following steps should be taken:
- Turn the ignition on (Run position) for 30 seconds, but do not start the engine. This allows the pump to prime the system.
- Turn the ignition off, and then crank it for 15 seconds.
- If it does not start, repeat the first two steps until it starts.
- If the engine starts but immediately stalls, wait for one minute before making another attempt.
- Once the engine starts, allow it to idle for several minutes and check for any leaks before driving.
It is important to note that if your diesel engine runs out of fuel, the dirt and leavings from the diesel that accumulate at the bottom of the tank will be consumed. This dirt can cause issues in the alimentation circuit, and a clearing will be needed. Additionally, if you have a CP4 injection pump, it is vulnerable to running dry and may require a new fuel system if damaged.
Understanding Diesel Mechanical Fuel Pumps: Metering Fuel Efficiently
You may want to see also
Explore related products
Priming the fuel system
If your diesel vehicle runs out of fuel, you will need to prime the fuel system. This is because, when the fuel runs dry, air gets sucked into the system and must be vented out. This process is known as "bleeding" the fuel system.
Some older diesel engines may require additional steps to bleed the fuel system. This can involve loosening fuel-line union nuts at the injection pump or finding the location of the bleeder screw, which is typically on the fuel filter housing. It is important not to completely remove these nuts or screws, only to loosen them.
It is important to note that attempting to start a diesel engine without fuel can damage injectors and other parts due to a lack of lubrication. Therefore, it is recommended to prime the fuel system properly before attempting to start the engine.
Installing a Fuel Pump: Isuzu NPR Diesel Guide
You may want to see also
Explore related products
Avoiding damage to the engine
While running out of diesel fuel may not damage the engine itself, it can cause serious issues with the fuel system. This is because the fuel pump may start sucking air into the system, which can then get trapped, and the engine will not restart until this air is removed. This process is known as "bleeding" the fuel system, and it can be time-consuming and messy.
To avoid damaging the fuel system, try not to let your fuel levels get too low. Keep an eye on your fuel gauge and be mindful of your approximate mileage range. If your fuel light comes on, don't ignore it—refuel as soon as possible to avoid issues.
If you do run out of fuel, do not try to start the engine without first refilling the tank. Once you've added fresh diesel, turn the ignition to the "Run" position for 30 seconds, but do not start the engine. This allows the pump to prime the system. Then, turn the ignition off and crank it for 15 seconds. If the engine does not start, repeat the process until it fires up.
If your vehicle has mechanical fuel injectors, you may need to loosen the fuel-line union nuts at the injection pump one by one. Alternatively, find the bleeder screw (usually located on the fuel filter housing) and loosen it a few turns without removing it completely. This will allow you to bleed the air out of the system.
Newer vehicles are often self-priming, which makes the process easier. However, it's still important to be cautious and follow the proper steps to avoid any potential damage to the fuel system.
Get Rid of Diesel Odor on Clothes
You may want to see also
Explore related products
What to do if your vehicle is on a steep grade
If your diesel vehicle runs out of fuel on a steep grade, the first step is to not attempt to start the engine without fuel as injectors and other parts could be damaged due to the lack of lubrication. If you have extra diesel, simply add more fuel to your tank and restart the engine.
If you do not have additional diesel, the next step is to bleed the fuel system to eliminate air pockets and restore proper fuel flow. This can be done by finding the bleeder screw (or Schrader valve) and loosening it a few turns. Do not remove it completely. Then, using a compressor, pump air into the fuel system via the filler neck, or crank the engine without starting it until fuel and air bubbles flow from the bleeder.
If your vehicle is on a steep grade, more than 5 gallons (19 litres) of fuel may be required to restart the engine. You must also purge any trapped air from the system before restarting the engine. To do this, switch the ignition on for 30 seconds and then switch it off. Repeat this process six times in a row. If the engine does not start after several attempts at priming, take a break and then repeat the process. Once the engine starts, allow it to idle for several minutes and check for any leaks before driving.
It is important to note that running out of fuel on a steep grade can be dangerous, as it can cause the vehicle to stall or shut down unexpectedly. If possible, it is recommended to keep an eye on the fuel gauge and refuel before embarking on steep grades to avoid this situation.
Why Diesel Engines Need Dual Fuel Filters
You may want to see also
Frequently asked questions
First, do not try to start the engine without fuel as this could damage the injectors and other parts due to a lack of lubrication. Next, add 4-5 gallons of diesel fuel. If your vehicle is on a steep grade, you may need to add more than 5 gallons. Then, bleed the fuel lines and injectors. Finally, prime the fuel system by turning the ignition on for 30 seconds, then turning it off. Repeat this process until the engine starts.
Bleeding the fuel lines and injectors can be messy, and is typically done with a wrench, a bottle or receptacle to collect the diesel, and some rags. For some engines, you will need to loosen the fuel-line union nuts one-by-one at the injection pump. For others, you will need to find the bleeder screw or bolt, which is typically located on the fuel filter housing.
Your vehicle will shut down when it runs out of fuel. If your fuel pump sends air through your fuel system instead of gas, your vehicle will not restart until the air is removed.
