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How To Free Up Stuck Injection Pump

Posted by Scott Goldfarb on

The diesel engine's heart, as we like to say, is the injection pump. But what happens when it gets jammed or doesn’t work properly? In that case, you have to learn how to free up stuck injection pump.

Well, don’t panic! Most of the time, you can fix it by yourself if you know your way around with tools. However, you must fix it as soon as possible. So, our guide will provide some expert tips on being sure if you have a stuck injection pump and how to prevent it in the future.

How to Free Up Stuck Injection Pump
Source: shutterstock.com/ Photo Contributor: kanemme6

Troubleshooting a Stuck Diesel Injector Pump

Before we jump off to the main topic and show you how to free up stuck injection pump, you must be sure you are treating the right problem. Therefore, several signs may indicate that the injection pump on your diesel vehicle is not working properly.

Improper work of the engine

The primary function of the injection pump is to induce high pressure so that the diesel fuel can reach the fuel injectors. They are complex diesel vehicle parts that must deliver the perfect pressure at the right time.

Hence, the engine won’t run smoothly if an injector pump malfunctions. Also, a stuck injection pump will affect the performance of your vehicle. So, three of the signs that are easily detectable and might mean you need to free up the injection pump are:

  • The engine starts to sputter like it is running out of fuel.
  • The engine loses power.
  • The engine misfires because of inconsistent fuel supply.

Expert tip: Most diesel vehicles won’t show the above signs at low speeds. Instead, the engine might start to sputter or lose power when accelerating or driving at a higher speed.

Difficulting starting

Another sign that your injection pump might be stuck is difficulty starting. As you know, the fuel gives power to the vehicle. Suppose the injection pump, responsible for providing enough pressure and generating enough fuel flow to the engine, doesn’t work correctly. In that case, your car won’t start or have difficulty running.

Injection pump codes

Before you go on with the steps on how to rebuild an injector pump on your car, it might be best to also run a diagnostic. It is one of the fastest and safest ways to determine whether you have a malfunctioning injection pump. 

Here are the most common codes for injection pump malfunction and their meaning:

  • P0215 - Fuel Injection Pump Control Circuit
  • P0217 - Injection Timing Control Circuit Low
  • P0218 - Injection Timing Control Circuit High
  • P0252 - Fuel Injection Pump Fuel Valve Stuck
  • P0253 - Injection Pump Fuel Metering Control Low

Smoky exhaust

A smoky exhaust may mean a lot of things. One of them is that you have a dirty or faulty injection pump that is not working as it should. 

If you see an unusual amount of smoke coming from your exhaust, or more precisely, gray, blue, or black smoke, your injection pump is probably not working properly.

How to Free Up Stuck Injection Pump

A stuck-up injection pump is most commonly a problem with diesel agricultural vehicles like tractors. However, it might also happen to diesel cars. Generally, the process of fixing a jammed injection pump is almost the same for all diesel vehicles because their engines work on the same principles.

So, here is a short overview of the steps:

  1. Ensure the engine and ignition are turned off.
  2. Check if there is fuel in the fuel tank.
  3. See if there are any air leaks in the fuel lines and connections.
  4. Check if there is dirt on the injection pump; if there is, clean it with a cloth and ensure there is no more debris.
  5. Spray penetrating oil like WD-40 or PB B’laster on the injection pump. You might need to let it soak overnight so you can continue unsticking a stuck injection pump.
  6. Gently tap the pump if necessary to help free it up.

You should know that diesel engines are lubricated from the diesel fuel. In some cases, using a diesel fuel additive may clean and lubricate the fuel system. Consequently, the stuck injection pump might also free up from the additive. 

If you choose to try out this method, use the additive as the manufacturer recommends and stick to the dosage.

What If You Can’t Free Up a Stuck Injection Pump?

If you can’t fix the issue with injection pump lubrication and restoration, you might need to get a new one installed. In times when the China aftermarket has taken a considerable amount of the spare parts industry, with us at Goldfarb and Associates, you can order high-quality and original pump injectors.

Aside from new, we also offer used and rebuilt diesel engine fuel injections. You can order injection pumps online from different manufacturers, including Bosch, Stanadyne, Delphi, and Denso.

You will know it is time to contact us if you notice some of the signs that indicate you need a new injection pump, like:

  • Sputtering below the RPM floor
  • Oxygen sensor issues
  • Turbocharger lag
  • Fuel tank noises

In these cases, a repair will probably be just a waste of your time.

Ways to Prevent Injection Pumps from Getting Stuck

If you want to avoid going through the steps on how to free up stuck injection pump again, you can take some precautions. To do so, you must understand the reasons why it happens. Here are the most common causes:

Ways to Prevent Injection Pumps from Getting Stuck

Source: shutterstock.com/ Photo Contributor: Voyagerix

Low-quality diesel fuel

Not every diesel fuel has the same quality. In fact, the fuel quality is dependent on the cetane number. In other words, diesel fuels have different speed and efficiency of combustion. Other factors influencing the quality of diesel fuel are its stability and contamination levels.

Understandably, the higher quality diesel fuel you use, the lesser the chances of getting a stuck injection pump. 

Driving with a near-empty fuel tank

The pump wears out quickly if you are running the car with a near-empty fuel tank. In this situation, there is a chance the diesel pump fuel injector will get an improper mix of fuel and air, with air being more dominant.

So, we always recommend keeping at least one-third of the tank full. That way, you might prolong the life of the injection pump and the entire fuel system. The fuel lubricates the injection pump and allows it to work efficiently.

Poor maintenance

The fuel filter also has an important role in the fuel system. It is the one responsible for depositing dirt and other substances that can be found in diesel fuel. Suppose the filter doesn’t work correctly because you haven’t changed it in a long time or used a low-quality one. In that case, you might experience malfunctioning of the injector pump and higher risks of it getting stuck because of dirt build-up.

Dirt and debris

It often happens for objects to get caught in the injection pump. It could be anything from dust to leaves. Although it seems impossible, such small things that are lodged inside the injection pump can cause your vehicle to have engine problems.


Knowing how to free up stuck injection pump can save you a lot of money and a visit to the mechanic. Also, you should pay more attention to your vehicle and properly maintain it.

Sometimes, even if you do everything right and on time, your car might start acting up and need new parts. Then, you can contact us, and we will give you the best prices for the part you are looking for. Almost all of the parts you can get from us are original and high-quality.

Ultimately, we hope this article was of real help to you.


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