FASS FASD08100G Adjus Diesel Fuel Pump Lift 850044137091 Adjus. 100GPH 5.9L

( Brand: Fass ), ( Manufacturer Part Number: FASD08100G ), ( Part Type: Fuel Pump Lift ), ( UPC: 850044137091 )

Review FASS Adjus. Diesel Fuel Lift Pump 100gph Dodge 5.9l fits CUMMINS 1998–2004

The **FASS FASD08100G Adjustable Diesel Fuel Lift Pump** is a high-performance, precision-engineered component designed specifically for the **1998 2004 Dodge Ram with the Cummins 5.9L diesel engine**. This lift pump is a critical part of the fuel delivery system, responsible for maintaining consistent fuel pressure and ensuring smooth, reliable operation under demanding conditions. Built to exacting standards, the FASD08100G features an **adjustable flow rate** of **100 gallons per hour (GPH)**, allowing for fine-tuning to optimize fuel delivery based on engine demands, load conditions, or modifications. Its robust construction includes a **durable brass or stainless steel body**, resistant to corrosion and wear, while the internal components are engineered for longevity, reducing the risk of leaks or failure over time. The pump s design incorporates a **positive displacement mechanism**, ensuring a steady and uninterrupted fuel supply to the injectors, which is essential for maintaining power, efficiency, and emissions compliance in the Cummins engine. Whether used in stock applications, performance builds, or heavy-duty towing scenarios, this lift pump delivers the reliability and precision needed to keep the 5.9L Cummins running at its best. Its compatibility with the **1998 2004 Dodge Ram** lineup makes it an ideal upgrade for owners seeking to enhance fuel system performance, reduce the risk of fuel starvation, or address issues related to fuel pressure fluctuations. With its adjustable flow rate and high-quality materials, the FASS FASD08100G is a dependable choice for maintaining or improving the fuel delivery efficiency of one of the most legendary diesel engines in truck history.

**Pros and Cons of buying a FASS FASD08100G Adjustable Diesel Fuel Lift Pump (100 GPH) for a 1998-2004 Dodge Cummins 5.9L**

### **Pros**

1. **Compatibility** The pump is specifically designed for the Dodge Cummins 5.9L engine (1998 2004 models), ensuring proper fitment with the factory fuel system components.

2. **Adjustable Flow Rate** The adjustable feature allows fine-tuning of fuel delivery to match engine demands, which can help optimize performance and fuel efficiency.

3. **High Flow Capacity (100 GPH)** Sufficient for most stock and lightly modified Cummins applications, reducing the risk of fuel starvation under moderate loads.

4. **Durability** FASS is a reputable brand known for producing reliable fuel system components, often built to withstand the demands of diesel engines.

5. **Easy Installation** Designed to replace the stock lift pump with minimal modifications, making it a straightforward upgrade for DIYers.

6. **Improved Fuel Delivery** A well-functioning lift pump ensures consistent fuel pressure, reducing the risk of fuel starvation during acceleration or under load.

7. **Cost-Effective Upgrade** Compared to full fuel system overhauls, this is a relatively inexpensive solution for addressing common lift pump issues.

8. **Reduces Risk of Fuel System Failures** A failing lift pump can cause hard starts, stalling, or even long-term damage to injectors or the fuel rail. A reliable replacement mitigates these risks.

### **Cons**

1. **Not a High-Performance Solution** While adequate for stock or mildly modified engines, it may not be sufficient for heavily turbocharged or high-horsepower builds requiring significantly higher fuel flow.

2. **Requires Proper Installation** Incorrect installation (e.g., improper sealing, wiring, or pressure adjustments) can lead to leaks, electrical issues, or reduced performance.

3. **Dependence on Other System Components** If the fuel filter, injectors, or fuel lines are degraded, the pump alone won t fully resolve fuel delivery issues.

4. **Limited Adjustability Range** The "adjustable" feature may not provide enough flexibility for extreme tuning scenarios, requiring additional components (e.g., a fuel pressure regulator) for precise control.

5. **Potential for Compatibility Quirks** Some users report minor fitment issues with certain Cummins configurations (e.g., fuel rail or bracket modifications), though this is rare with a well-matched part.

6. **No Warranty on Aftermarket Pumps** Unlike OEM parts, aftermarket pumps may not come with long-term warranties, leaving the buyer responsible for any failures.

7. **Electrical Reliability Concerns** If the wiring harness or relay is faulty, the pump may not activate properly, requiring additional troubleshooting.

### **Conclusion**

The FASS FASD08100G adjustable diesel fuel lift pump is a solid, practical choice for restoring or upgrading the fuel delivery system in a 1998 2004 Dodge Cummins 5.9L. It addresses common lift pump failures while offering adjustable flow for better performance tuning. However, it is not a high-flow solution for extreme builds and requires proper installation to function correctly. For most stock or lightly modified engines, this pump provides a reliable, cost-effective upgrade with minimal downsides.

### **Recommendation**

- Your Cummins is experiencing lift pump-related symptoms (hard starts, stalling, poor idle).

- You want a simple, adjustable upgrade without overcomplicating the fuel system.

- You re not pursuing extreme power levels (e.g., 1,000 HP) that would require a higher-flow pump.

- You re comfortable with basic installation and troubleshooting.

- You re building a high-horsepower engine and need a pump with significantly higher flow (e.g., 200 GPH).

- You suspect other fuel system issues (e.g., clogged injectors, bad fuel lines) that would require a full overhaul.

- You prefer OEM-level reliability and are willing to pay for a factory replacement pump.

- Pair the pump with a high-quality fuel filter and clean fuel lines for optimal performance.

- Follow the manufacturer s installation guidelines closely, especially regarding wiring and pressure adjustments.

- If tuning the engine, monitor fuel pressure and adjust the pump accordingly to avoid rich or lean conditions.

Details:

Cummins Adjustable High Performance System Features: Whisper Technology. FASS FASD08100G Adjus. Manufacturer: FASS. FASS Fuel Systems Signature Series Adjustable Diesel System 100GPH 1998 .5-2004 Dodge Cummins 5.9L FASD08100G, Part No: FASD08100G.

All Mounting Hardware Included. Built In Fuel Pressure Gauge Port. To aid in proper performance we built a boost compensation port, air pressure from your intake manifold raises fuel pressures while under full throttle, maintaining when it matters most. This is a fuel System only and must be used with your factory filter.

Condition: New. MPN: FASD08100G. Our FASS Fuel Systems Signature Series Adjustable Diesel are designed to be the most versatile high performance fuel System on market that allows for adjustable pressures meet demand of Dodge Cummins 5.9L applications. Items must be New, Unused, Not Installed, in the Original Packaging and able to resold.

Improves Fuel Flow.

part #: fasd08100g prices

• $547.99-$549.00

specifications automobilefluids:

• for models: Cummins
• for makes: Dodge
• for years: 1998-2004
• brand: Fass
• mpn: Fasd08100g
• part type: Fuel Pump Lift
• upc: 850044137091

seller automobilefluids:

• # reviews: 168668
• rating: 99.2%
• city: Grant, Michigan

returns automobilefluids:

• policy: Returns Accepted
• paid by: Seller
• time: 30 Days

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• cost: $0.00
• type: Fixed
• service: Expedited
• class: Expedited
• transit: 3-7 Days

general automobilefluids:

• Automotive Tools Supplies > Fluids Chemicals > Other Fluids Chemicals
• condition: New

offer automobilefluids:

• availability: In Stock
• started: February 4, 2026
• sold: 0
• options: Ship-to-home
• quantity: 1

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• other
• wallet: Apple-pay
• credit card: Diners-club

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