When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Price: $998.99
Complete Fuel Pump Assembly for V12 BMW E31 850i 850ci and 850CSI.
M70 engines (1990-1994) S70 engines (1992-1997).
Located under the passenger rear seat.Includes top rubber seal.
I receivedseveral questions and would like to clarify, this is NOT a 3D printed part. This pump has been in development for over 2 years and every component is precision injection molded just like the factory, with all shortcomings of the original design engineeredout.
Changes and Improvements to the original pump design:First, the most glaring problem is that up to 40% of the original fuel pump assemblies (both 850 and 840 units) begin to leak fuel at the what's called mold "parting line" at the top of the assembly right below the injection point mark. I believe this is a factory production miss where the parting line should have been reinforced and water cooled more sufficiently. After thermal expansion and contraction over the years micro cracks appear down this line and fuel starts to leak! My new design completely eliminates this issue making the top cap universally strong and crack resistant for a long term!BMW pump assembly has brittle plastic preformed fuel lines mating to the rubber hoses and then to the fuel pump motor. This design mayhave been OK 30 years ago, but with introduction of modern more corrosive fuels like E10 in Europe and Ethanol additive in US it quickly degrades resulting in major pressure leaks at the fuel pump motor connection as well as through cracks in the old plastic lines themselves. Result is rough idle, low power on one or both banks and lean running condition. In fact, every single original unit I rebuilt had this issue. My design is a vast improvement over original by using high pressure fuel resistant corrugated PTFE lines running directly from the top of the pump unit to the pump motors eliminating the need for rubber hoses.Lines are heat pressed onto fuel pump fittings and then clamped ensuring no pressure leaks EVER.Original BMW wiring is insulated in material which has only partial resistance to regular fuel not to mention E10. Wires delaminate with time creating electrical shorts! I use only expensive 600v military grade PTFE insulated wire that will practically last forever inside the tank. Ground wire connection has also been re designed to eliminate exposed crimped 1 to 2 wire split joint which lowers the risk of shorting.Original BMW fuel pump motors have copper commutators. They have been replaced with modern, very quiet, carbon commutator motors that last 3 times longer in fuel. New pump motors are capable of up to 150 LPH each on demand (up from OEM 110 LPH) and maintain factory pressure 3 BAR pressure precisely.The fuel level sensor, although similar in shape, has been re-engineered with modern components to be more precise and extremely long lasting.E31-V12throttle.com
Don't forget to check out my other E31/E32 specific items available for sale!