What Is A Lift Pump Diesel?

Stock just won’t cut it when it comes to your diesel application, or any application for that matter. Factory components and mechanics can last for many years, but eventually you’ll need to update your diesel engine’s performance. Upgrades can be hard, and the majority of them require you to complete prep tasks before you can start swapping parts.

The diesel fuel lift pump is one of the elements that is eventually replaced with a better functioning model.

What is a lift pump?

It’s essentially a gasoline delivery pump that distributes fuel from the tank to the injection system. Most diesel engines are equipped with a fuel pump, whether it’s a mechanical injection system found in older versions or a pump built into the engine itself in newer models.

Why would you need a new one?

Engine tuning with aftermarket and performance parts isn’t a new notion, and it extends far beyond the diesel world. Almost everyone wants to improve something about their engine, whether it’s a gas, diesel, or vegetable oil engine (not sure how many upgrades are available for a deep fryer, though). Adding a new pump to your diesel engine can drastically enhance its performance way beyond the manufacturer limits, despite the fact that diesel engines have the most efficient internal combustion of any engine type.

How would you go about it?

The modification’s purpose is to increase the amount of fuel injected into the engine. This process would begin with increasing fuel flow by computer programming (newer models) or the installation of high-flow injectors. You’ll inevitably need to upgrade your pump when the engine demands more fuel. Low fuel pressure results in lower horsepower and, in certain circumstances, injection pump breakage.

It’s crucial to remember the first word: diesel, while determining which lift diesel lift pump to buy. There are certain gasoline pumps that can be converted to diesel, but they will eventually fail, perhaps instantly. Consider a pump and filter combo that provides both performance and better, higher-capacity filtering.

If you want to improve the performance of your diesel engine, come see us now for Fass fuel filters, pumps, and more.

What is the purpose of a diesel lift pump?

A lift pump’s job is to deliver low-pressure gasoline (from the tank) to the engine’s injection pump. Most lift pumps, whether aftermarket or OEM, deliver 8 to 15 psi of supply pressure (aside from the 7.3L, 6.0L and 6.7L Power Stroke engines, which call for 45-to-65 psi). The injection pump or injectors pressurize the fuel that makes its way into the cylinder between 15,000 and 30,000 psi (depending on the engine and injection system the engine has).

The injection pump would have to pull fuel all the way from the fuel tank if it wasn’t supplied with low-pressure fuel via the lift pump (which is the case in Duramax applications). Its life duration is considerably shortened if there is insufficient fuel going into the low-pressure side of the injection pump. Continued deprivation of fuel will eventually harm the injection pump and possibly the injectors.

What is the difference between a lift pump and a fuel pump?

In conjunction with a fuel injection system, modern gasoline pumps enable automobiles to travel at faster speeds while also improving fuel economy. Lift pumps contribute to this system by providing suction and controlling air flow to help raise the level of gasoline in the engine block. In an automobile’s fuel management system, these two distinct systems provide complementary roles, which is critical in contemporary high-performance automobiles.

Do all diesels have lift pumps?

Almost every diesel enthusiast has heard the term “lift pump” at some point. However, there are still some unanswered issues about the topic, such as what exactly is a lift pump and what kind of lift pump you require.

Simply described, a lift pump is a supply pump that transports fuel from the tank to the injection system of the engine. From antique mechanical injection systems to Ford’s HEUI system to current common-rail rigs, virtually every diesel has a lift pump of some type. Even engines like GM’s Duramax get fuel from the tank using a factory lift pump incorporated into the engine’s high-pressure CP3 pump.

So, if your engine already has a lift pump, why would you acquire an aftermarket lift pump? When it comes to increasing the power of a diesel engine beyond the factory specifications, one of the first changes that is made is to increase the amount of fuel injected. This can be done either mechanically (if the truck is computer-equipped) or by programming (if the truck is computer-equipped). The factory lift pumps are always one of the first sections of the system to fail when the engine’s fuel demand is pushed up to overdrive.

When the supply fuel pressure lowers, the injection pressure in the engine drops, and the engine’s horsepower drops as well. Running pressure that is too low in some circumstances (such as VP44 pumps found on 1998.5-2002 Dodges) might actually injure the injection pump and cause it to fail. When an engine is upgraded for increased power and performance, it’s a good idea to upgrade the lift pump as well.

The issue is that there are a number of lift pumps on the market. Low-pressure fuel pumps for gasoline systems are an appealing alternative with prices around $100, but they nearly invariably fail in a diesel application. Some pumps have lasted for years, while others have only lasted a few weeks. Some will fail completely, while others will simply begin to leak. An inexpensive lift pump intended as a fuel pump for a gasoline application, on the other hand, will almost always fail.

There are a plethora of diesel-specific alternatives on the market. Carter, PPE, and Aeromotive are just a few of the companies that manufacture diesel-specific pumps. Pump and filter combos are also available, which provide greater filtration, fuel-air separation, and higher-flowing filters that match the performance pump’s capabilities. These filter and pump configurations are by far the most prevalent option in the diesel sector, with manufacturers such as Airdog, FASS, Fuelab, and BD Diesel producing kits that are widespread on most diesel trucks.

Carter P4601HP

For the do-it-yourself set, Carter offers one of the most popular lift pumps. The Carter P4601HP pump has a flow rate of about 100 gph at 18 psi and doesn’t need an external regulator. These pumps are long-lasting, quiet, and suitable for low- to medium-horsepower vehicles.

Walbro 392

Many older 7.3L Ford diesels don’t require a lot of flow, but they do require pressure. Walbro GSL392 fuel pumps can be used to push enough of #2 diesel to the engine in these high-pressure applications. The Walbros, like the Carter, are quiet, long-lasting, and can be used with an external regulator for low-pressure applications. They have a flow rate of 68 gph at 60 psi.

Aeromotive A1000, Eliminator Series

Aeromotive fuel pumps, the granddaddy of homebuilt fuel systems, have been employed in high-horsepower applications for many years. The size of the feed and return lines on the Aeromotive pumps is critical, as small lines put too much strain on the motors, causing them to burn out. The Aeromotive pumps are a little louder than the Carter or Walbro pumps, but for the volume of fuel they can flow, they’re actually rather quiet. The Aeromotive A1000 pump has a flow rate of 145 gph and a pressure range of 20 to 80 psi, while the Eliminator pump has a flow rate of 250 gph and is well suited to competitive engines.


Airdog, one of the first fuel-air separator manufacturers, offers a variety of complete kits for Ford, Dodge, and GM diesel engines, including lines, filters, and pumps. From the self-regulating 100-gph Raptor series to the large 200-gph AirDog II pumps, the AirDog series comes in a variety of sizes and flow parameters. They’ve also released a new 4G model with a low-amperage engine and an intermediary shaft that prevents leaks by separating the air from the fuel. If you need a complete fuel system, AirDog is one of the companies that can provide it.

BD Diesel

While BD Diesel has been making lift pumps for a long time, they have just added a filter and a water separator to their product range, making it a complete kit. The Flow-Max Series of lift pumps uses filters available at local hardware shops, and their pump is an ultra-quiet model that is up to 16 decibels lower than the competitors. The lift pumps from BD have a flow rate of 150 gph at 15 psi.


FASS, another manufacturer with a long history in the diesel lift pump industry, offers everything from factory replacement lift pumps to ultra-high-flow units capable of 220 gph at 45 psi. FASS also manufactures pumps for Class 8 semis, making its lift pump line one of the most diversified on the market. The filters in FASS applications are intended to match the pump’s flow rating, and FASS units come in both low-pressure and high-pressure versions. Twin 220-gph pumps can sustain horsepower in the 1,500-2,000 hp range for demanding applications.


Fuelab, which has a long history in the gasoline racing scene, has just released the Velocity 100 and 200 series for most modern diesel trucks. The Fuelab series features a single water separator/filter and a high-performance low-amp motor. The Fuelab series’ filters may be cleaned or replaced, and the system comes with a two-year warranty. For Ford, Dodge, and GM applications, Fuelab offers complete kits in either the 100 or 200 gph series.


There are numerous of lift pump alternatives available, whether you want to do it yourself or buy a whole kit. Most 100- and 150-gph lift pumps will handle horsepower levels between 500 and 700 rwhp, whereas anything above 700 rwhp will require a bigger 200 or 250-gph pump, or two smaller pumps. Remember that a loss of pressure means a loss of dependability and power, which we all know diesel owners don’t want!

What are the benefits of a lift pump?

Lift pumps have numerous advantages. Lift pumps are an important aspect of truck customisation, particularly if the goal is to increase power. They’re not as flashy as a supercharger, but they’re just as important. They increase fuel volume while simultaneously improving filtration, allowing for higher-quality gasoline to pass through the system.

Do I need a lift pump on my Duramax?

The Duramax is the most responsive to a lift pump aftermarket. The GMC and Chevy Duramax pickup trucks do not have a fuel lift pump. The CP3 injection pump is the truck’s only means of delivering fuel from the tank to the engine from the manufacturer. If you have a look at our movie, you’ll see that “It will show you what happens when the CP3 pump pushes fuel from the tank to the engine in “How the AirDog Works.” As a result of the constant suction, cavitation and severe wear and tear on injectors and your injection pump occur. Also, when adding aftermarket programmers or tuners that increase the demand for fuel, this is the leading cause of low rail pressure problems. You get the added benefits of smoother and quieter idle, better throttle response, increased fuel economy, better mid-range through top-end power, and more consistent rail pressure to support both stock and modified engines by providing both constant positive fuel pressure and 100 percent pure fuel to the engine.

Because we have a few different Duramax systems, the installation complexity and time will change. The AirDog II, FP100, and Raptor pump kits, for example, do not require you to remove the tank in order to install the system. The AirDog II’s suction line connects to the factory fitting on the fuel tank sending unit, thanks to our OEM style quick connect fittings and internal pump design. If you want to add an AirDog FP150, you’ll need to remove the tank and install a 1/2 suction tube. A suction tube is not required for any of the Raptor kits.

As for the rest of the installation, all of the systems will hook up to either the factory steel feed line that runs up to the engine or the line immediately on the engine for fuel delivery; we give you the option of hooking up to either area based on your mechanical skills. The entrained air and un-used fuel from the AirDog and AirDog II systems will be transferred back to the tank via the fuel filler tube. When using any of the AirDog or Raptor fuel systems, the factory fuel filter housing will be retained.

Many people wonder why the AirDog II doesn’t require the 1/2 suction tube because of its increased flow rate. The reason for this is due to the internal architecture of the AirDog II. The AirDog II recycles fuel back through the base to keep the system full at all times, resulting in minimal waste and making it a real zero-emission aircraft “ON DEMAND” service. Also, all AirDog and AirDog II systems include a built-in pressure port on the top of the base just above the fuel filter that can be removed and used to monitor pressure. It’s plugged with a 1/8 pipe plug and can be removed and used to check pressure.

Is a diesel lift pump the same as a fuel pump?

A low-pressure fuel supply pump known as a fuel lift pump transfers fuel from the tank to the injection pump. The lift pump, which is most commonly used in vehicles with diesel engines, essentially produces pressure or suction in the gas tank, causing gasoline to rise to the injection system and engine.

The high-pressure injection pump or unit injectors, which often boost pressure to thousands of psi, pressurize the fuel pressure from the lift pump.

Will a diesel run without a fuel pump?

When a diesel truck runs out of fuel, it will not restart even if you get more diesel and put it in the tank. If the fuel line is full of air, a diesel will not pull fuel from the tank to the engine.

How long does a lift pump last?

The unsung hero of your automobile is the gas pump. It transports gas from the gas tank to the engine, allowing your car, truck, or SUV to start and run. The fuel pump in your car should last at least 100,000 kilometers. If it doesn’t, or if you’ve passed that distance mark, you might see one of the seven indicators below. Bring your car to Primary Care Auto Repair in Warwick, RI if this is the case.

Does a lift pump add power?

The majority of lift pump manufacturers tout superior water separation and supply pressure as reasons to buy their equipment, but in most circumstances, a higher-pressure lift pump can also enhance power. We saw approximately 35 more horsepower across the board in Project Triple Threat, our 1995 Dodge project, by increasing fuel pressure from 10 psi (at wide-open throttle) to 35 psi. While this pressure was higher than the factory recommended, it did assist add a lot of power. With a new Walbro lift pump, Feature Editor Mike McGlothlin’s 7.3L-powered Power Stroke gained 9 horsepower, illustrating that horsepower from supply pump pressure isn’t application specific.