1999 Dodge Cummins Fuel Pump Conversion Kit: The Ultimate Guide to Upgrading Your Lift Pump
Why You Need a Fuel Pump Conversion Kit for Your 1999 Dodge Cummins
The 1999 model year is a critical one for Dodge Cummins owners. It falls in the middle of the 1998.5-2002 generation that uses the VP44 injection pump, which is highly sensitive to fuel pressure. The factory lift pump on these trucks is often inadequate, especially as the vehicle ages. When the lift pump fails or loses pressure, the VP44 pump runs dry, overheats, and fails—a repair that costs thousands of dollars.
A conversion kit solves this problem by replacing the factory lift pump with a high-flow, more reliable aftermarket pump. These kits typically include everything you need: a new pump, mounting brackets, fuel lines, fittings, and wiring harnesses. They are designed to be a direct or near-direct replacement, making the installation straightforward for a DIY mechanic. The result is a fuel system that delivers consistent pressure, extends the life of your VP44 pump, and can even support increased horsepower if you upgrade your injectors or turbo later.
Understanding Your 1999 Dodge Cummins Fuel System
Before diving into the conversion kit, it helps to understand the basics of your truck's fuel system. The 1999 model uses a mechanical lift pump mounted on the engine, which pulls fuel from the tank and sends it to the VP44 injection pump. The VP44 then pressurizes the fuel for the injectors.
The factory lift pump is a weak point. It's a simple electric pump that often fails due to heat, age, or contamination. When it fails, the VP44 doesn't get enough fuel, causing it to run hot and fail. Many owners upgrade to a conversion kit that uses a more powerful pump, often mounted on the frame rail for better cooling and accessibility. This is sometimes called a "lift pump relocation" kit, and it's the standard fix for these trucks.
Key Factors for Your 1999 Model
- Lift Pump Location: The factory pump is mounted on the engine block. Conversion kits often relocate it to the frame rail, which reduces heat exposure and makes future servicing easier.
- Fuel Pressure: The VP44 needs at least 10-15 psi at idle. A good conversion kit will provide 15-20 psi or more, depending on the pump.
- Flow Rate: For stock trucks, a pump that flows 100-150 gallons per hour (GPH) is sufficient. For modified trucks, you may need 200 GPH or more.
What to Look for in a 1999 Dodge Cummins Fuel Pump Conversion Kit
Not all conversion kits are created equal. Here are the key features to consider when choosing one for your truck.
1. Compatibility with Your Exact Year
While 1998.5-2002 trucks share many similarities, there are differences. The 1999 model has specific fuel line connections and mounting points. Make sure the kit is explicitly designed for 1999 Dodge Cummins trucks. Some kits are listed as "1998.5-2002" but may require minor adjustments for the 1999 model. Always check the product description or contact the manufacturer. For example, the Fuelab 1998.5-2004.5 Dodge Cummins 100 Installation Kit (Model 20103) is designed for this generation and includes parts for different years.
2. Pump Type: Electric or Mechanical?
Most conversion kits use an electric pump. Electric pumps are more reliable, easier to install, and provide consistent pressure. They are mounted near the fuel tank or on the frame rail. Some kits use a mechanical pump, but these are less common and often not as reliable for high-performance applications.
3. Included Components
A good conversion kit should include:
- The pump itself: Choose a pump with a proven track record. Look for pumps that are rated for diesel fuel and have a good warranty.
- Mounting bracket and hardware: This allows you to mount the pump securely on the frame or a crossmember.
- Fuel lines and fittings: Many kits come with push-lok or -AN style fuel lines and the necessary adapters to connect to the factory fuel filter housing and tank.
- Wiring harness: A plug-and-play harness that connects to the factory electrical system is a huge time saver. Some kits include a relay and fuse for safety.
- Installation instructions: Clear, step-by-step instructions are invaluable, especially for a first-time installer.
4. Flow Rate and Pressure
For a stock 1999 Cummins, a pump that flows 100-150 GPH is plenty. If you plan on adding larger injectors, a turbo upgrade, or have a modified engine, you may need 200 GPH or more. The pump should deliver at least 15-20 psi at idle. Some adjustable pumps allow you to set the pressure to your exact needs.
5. Ease of Installation
The installation of a conversion kit is a moderate DIY project. You'll need basic tools: wrenches, sockets, a drill (for mounting holes), and possibly a jack and stands. The most difficult part is often removing the fuel tank, which is required for some kits to access the fuel sending unit. However, many kits allow you to avoid this by tapping into the fuel line near the tank or by removing the truck bed. The FlowMAX kit for 1998-2002 Dodge Cummins, for example, provides detailed steps for routing fuel lines and wiring, and the manual notes that removing the front driveshaft may be necessary for 4x4 models.
Step-by-Step Installation Overview for a 1999 Dodge Cummins
While every kit is different, the general installation process is similar. Here is a basic overview to help you understand what's involved.
Step 1: Safety First
Before you start, disconnect the negative battery cables (both batteries if you have dual batteries). Work in a well-ventilated area, away from open flames. Wear safety glasses and gloves. Diesel fuel is flammable and can be irritating to the skin.
Step 2: Gather Your Tools and Parts
You'll need:
- Your conversion kit
- Basic hand tools (wrenches, sockets, screwdrivers)
- A drill with a metal drill bit
- Jack and jack stands
- A container to catch fuel
- Zip ties for securing lines and wiring
Step 3: Remove the Stock Lift Pump
The stock pump is located on the driver's side of the engine block. Disconnect the fuel lines and electrical connector. Remove the mounting bolts and take the pump out. Be prepared for some fuel spillage.
Step 4: Install the New Pump Mounting Bracket
Most conversion kits include a bracket that mounts to the inside of the frame rail, near the fuel tank. Choose a location that is away from exhaust components and moving parts. Drill pilot holes if needed, then secure the bracket with the supplied hardware.
Step 5: Route the Fuel Lines
You'll need to run new fuel lines from the tank to the pump, and from the pump to the fuel filter housing. Most kits use 3/8" or 1/2" fuel line. Use the supplied fittings to connect to the fuel filter housing. For the tank side, you may need to install a new pickup tube or use a quick-connect adapter. The FASS DDRP 02 relocation kit for 1998.5-2002 Dodge Cummins, for example, includes a detailed process for connecting to the fuel filter housing and the tank sending unit.
Step 6: Connect the Wiring Harness
The wiring harness connects to the factory fuel pump harness. Follow the instructions to connect the wires to the pump, relay, and battery. Secure the wiring with zip ties, keeping it away from hot surfaces and moving parts. The FlowMAX kit instructions emphasize routing the wiring away from heat sources and securing it with tie wraps.
Step 7: Prime the System and Check for Leaks
Before starting the engine, prime the fuel system. Turn the key to the "on" position a few times to allow the pump to run and fill the lines. Check for leaks at all connections. If you have a filter housing with a bleeder screw, loosen it to bleed air out of the system. Once the system is primed, start the engine and check for leaks again.
Step 8: Final Checks
Verify the fuel pressure with a gauge if your kit includes one. The pressure should be within the manufacturer's specified range (typically 15-20 psi). Make sure all lines and wiring are secure.
Recommended Conversion Kits for the 1999 Dodge Cummins
Based on the available information, here are a few reliable conversion kits that work well for a 1999 Dodge Cummins.
1. Fuelab Velocity Series 100 Installation Kit (Model 20103)
This kit is designed for 1998.5-2004.5 Dodge Cummins trucks. It includes a 100 GPH pump, fuel lines, fittings, and a wiring harness. It's a good choice for stock or slightly modified trucks. The instructions are detailed and emphasize safety, such as draining the fuel tank and working in a well-ventilated area.
2. FlowMAX Lift Pump Kit
The FlowMAX kit is designed for 1998-2002 Dodge Cummins trucks. It includes a pump, mounting bracket, fuel lines, and a wiring harness. The installation manual is comprehensive, covering steps like removing the front driveshaft for 4x4 models and routing the wiring to the battery.
3. FASS DDRP 02 Relocation Kit
This kit is for relocating the lift pump on 1998.5-2002 Dodge Cummins trucks. It's a popular choice for owners who want to move the pump to the frame rail. The kit includes a pump, mounting bracket, fuel lines, and a filter. The instructions are clear and include torque specifications for all fittings.
4. AirDog Raptor RP-100 or RP-150
The AirDog Raptor pump is a well-known upgrade for 1994-1998 Dodge Cummins trucks, but it can also be used on 1999 models with some modifications. The RP-100 is for stock trucks, while the RP-150 is for modified trucks. The pump features a gerotor design and an adjustable pressure regulator. The kit includes a mounting bracket, fuel lines, and a wiring harness.
Why Choose KEMSO Fuel Pumps for Your 1999 Dodge Cummins
When it comes to reliable, high-performance fuel pumps, KEMSO is a brand you can trust. Their fuel pumps are designed as OEM replacements that deliver superior flow and durability. Whether you are looking for a direct replacement or a high-flow upgrade for a modified engine, KEMSO has a solution.
Key Features of KEMSO Fuel Pumps
- High Performance: KEMSO fuel pumps are engineered to provide consistent fuel pressure and flow, even under demanding conditions. They are ideal for both stock and modified vehicles.
- OEM Replacement: They are designed to fit perfectly in your 1999 Dodge Cummins, making installation straightforward. No custom fabrication is needed.
- Lifetime Warranty: KEMSO stands behind their products. Each pump comes with a lifetime warranty, giving you complete peace of mind.
Visit KEMSO Today
If you are ready to upgrade your fuel system, visit the KEMSO Racing website to explore their full range of products. They offer fuel pumps for a variety of vehicles, including the 1999 Dodge Cummins. With their high-performance pumps and lifetime warranty, you can drive with confidence knowing your fuel system is in good hands.
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Common Mistakes to Avoid When Installing a Conversion Kit
Even experienced mechanics can make mistakes. Here are a few common ones to watch out for.
1. Not Priming the System Properly
After installing the new pump, you must prime the fuel system. If you run the engine without priming, the injection pump can be damaged. Follow the instructions carefully, and be patient.
2. Using the Wrong Fuel Lines
Not all fuel lines are rated for diesel fuel. Some rubber lines can degrade over time, causing clogs or leaks. Use the fuel lines supplied with the kit, or purchase high-quality diesel-rated lines.
3. Overtightening Fittings
Fuel fittings, especially banjo bolts and quick-connect fittings, can be damaged if overtightened. Use a torque wrench when specified. The FASS kit instructions, for example, specify 18 ft/lbs for many fittings.
4. Routing the Wiring Near Heat Sources
The exhaust manifold and turbocharger get extremely hot. Make sure all wiring is routed away from these components. Use zip ties to secure the harness and keep it away from moving parts.
5. Skipping the Final Check
After the installation is complete, check for leaks, verify fuel pressure, and make sure all connections are secure. This simple step can save you from a roadside breakdown.
Maintaining Your New Fuel Pump Conversion Kit
Once you have installed your conversion kit, a little maintenance goes a long way.
- Regularly Check the Fuel Filter: A clogged filter can restrict flow and damage the pump. Replace it according to the manufacturer's recommendations.
- Inspect the Fuel Lines: Look for cracks, leaks, or chafing. Replace any damaged lines immediately.
- Check the Wiring: Ensure the connections are clean and secure. Corrosion can cause electrical issues.
- Monitor Fuel Pressure: If you have a pressure gauge, keep an eye on it. A drop in pressure could indicate a problem with the pump or a clogged filter.
Final Thoughts
Upgrading to a 1999 Dodge Cummins fuel pump conversion kit is a smart move for any owner. It protects your expensive VP44 injection pump, improves reliability, and can even boost performance if you plan future modifications. The installation is a manageable DIY project if you have basic mechanical skills, and the payoff is a fuel system you can trust for years to come.
Remember to choose a kit that is specifically designed for your 1999 model, and don't cut corners on quality. A reliable pump like those from KEMSO will serve you well.
For high-quality fuel pumps and conversion kits, visit KEMSO Racing today: https://www.kemsoracing.com/