The BMW E31 Fuel Pump is a complete, high-quality fuel pump assembly designed for the BMW E31 850i, 850ci, and 850CSI models with M70 and S70 engines (1990-1997). Positioned beneath the passenger rear seat, this assembly includes a top rubber seal and incorporates several key upgrades to correct common issues with the original design.
The primary issue with the original BMW fuel pump assembly was fuel leakage, particularly from the mold parting line located at the top of the unit. Over time, micro cracks formed, resulting in fuel seepage. The newly designed fuel pump assembly eliminates this issue by reinforcing the top cap for a more durable, crack-resistant structure.
Additionally, the original plastic preformed fuel lines have been replaced with high-quality, high-pressure PTFE corrugated fuel lines, making the system more resistant to modern fuels like E10 and ethanol. These new lines provide superior performance by preventing pressure leaks that were common with the older design.
For improved safety and longevity, the wiring has been upgraded to military-grade PTFE insulation, which is highly resistant to fuel and will not degrade over time. The fuel pump motors have also been redesigned, now using carbon commutators instead of copper ones. These carbon motors are quieter, more durable, and last up to three times longer than the original copper commutator motors, providing a reliable and efficient fuel delivery system.
Lastly, the fuel level sensor has been re-engineered with modern components for better precision and durability, ensuring a more reliable fuel gauge.
BMW N54 3.0L Stage 2 LPFP Spool Performance Bucketless is engineered by Spool Performance, a leading name in BMW forced induction, to deliver exceptional fuel delivery and power upgrades. Designed by a team of dedicated engineers, this high-quality component enhances your vehicle's fuel system with superior performance.
The Precision Raceworks G8x/G2x Stand Alone Auxiliary Fuel System is the highest-performing and most stable low-pressure fuel system on the market! Forget about how things have been done and embrace the benefits of dedicated fueling for your port injection!
Since direct injection came out for BMW, enthusiasts have been adding port injection. With this came the need to upgrade the low-pressure fuel system to keep up. Historically this was done by increasing the output of the main fuel system. Unfortunately, the main fuel pump is controlled using PWM by a factory programmed controller designed to reduce output when target fuel pressure (typically 5 bar) is exceeded, creating a constant battle when pumps are added or upgraded. This limits upgraded fuel pumps from performing to their full potential.
Additionally, the high-pressure pump control system dumps fuel back into the low-pressure system at high pressure low volume resulting in oscillations of the low-pressure fuel system. Because of this, the DI system in the car is required to constantly make corrections to keep target AFR in check.
With this stand-alone low-pressure fuel system dedicated to your port fueling that is a thing of the past! Get rock-solid fuel pressures at any pressure, run fuel pressures that are 1:1 scalable to boost pressure, flow more fuel with dedicated lines, run smaller injectors and still get more fuel than you did with large injectors (allowing for higher resolution), put less demand on the car’s DI system to correct for fluctuations in pressure, even your tuner will be grateful as the system makes tuning of port fueling even easier and more accurate, the list of benefits goes on and on!
Features & Benefits
Billet Aluminum top hat with 3 high-flow fuel ports
Dedicated fuel pump(s) for port injection system
Optimal pump location resistant to fuel slosh under acceleration
Fully adjustable 1:1 scaling billet fuel pressure regulator
10-micron USA made Microglass fuel filter (Ideal for E85)
Smooth bore high flow PTFE fuel feed & return lines (AN6)
All billet connections for both fuel line fittings and top-hat
Plug and play connectors inside and outside* the top hat
Configurable pump activation harness (see instructions for more details)
Increased injector flow (when using 1:1 regulator feature vs static)
Compatible with all stock or upgraded primary fuel pumps
Easily expandable and upgrade-able for more fuel
All components and parts feature 100% Ethanol Compatibility
The AFS.800 dedicated auxiliary fuel system comes with all** necessary components to provide dedicated fuel system for port injection. Featuring Two Walbro 535’s (F9000295) fuel pumps with a combined flow of 800LPH at 3 bar.
Pump flow 43.5 psi-a : 800 lph
Recommended base pressure: 43.5 psi-g
Maximum Fuel Pressure: 110 psi-g
Number of Fuel Output Ports: 2
Number of Fuel Return Ports: 1
Pump 1: Walbro 535 (F90000295)
Pump 2: Walbro 535 (F90000295)
Available (unused) Electrical Connections: 2*
Total System Weight:14 lbs (including fuel lines and wiring harness)
*At time of install some wiring in the car may need to be cut and spliced to connectors included in this kit
**Male AN8-ORB to Female AN6-ORB adapter may be required for compatibility with some fuel rails (not included in kit)
Upgrade your BMW's performance with the BMW Gen2 B58 FX350 Upgraded High Pressure Pump. This high-quality pump is designed to deliver increased fuel pressure, ensuring optimal engine performance and reliability for your BMW.
BMW S55 Stage 3 Low-Pressure Fuel-Pump is an advanced upgrade designed to significantly enhance your vehicle's fueling system. Engineered by Spool Performance, a leader in the BMW Forced Induction industry, this fuel pump provides a substantial increase in fuel flow to support high-performance driving. The Stage 3 Low-Pressure Fuel-Pump more than doubles the flow rate of the stock fuel pump and is fully compatible with E85 fuels. It offers a plug-and-play installation for easy integration and comes with a lifetime warranty for peace of mind.
This product was last offered at the strikethrough price on
07-28-2026
This product was last offered at the strikethrough price on
07-28-2026
