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QFS Inline or Intank High-Flow Viton Fuel Pump Check Valve 8mm (5/16")

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0.12 LBS
A common side effect of high volume (and OEM) in-tank fuel pumps are their inability to maintain static fuel pressure when the vehicle sits for any extended period of time. This leads to a "hard starting" condition where the starter must engage continuously for 3-4 seconds (or longer) before the motor will finally start. This side effect is commonplace with all high performance, high volume fuel pumps, including Walbro, AEM, Aeromotive, and Quantum fuel pumps. Our check valve resolves this issue once and for all, and can be used either in-tank or externally. It features a high-flow design which uses viton seals and stainless steel internals which are compatible with modern pump gasoline as well as E85. This check valve will not significantly alter the flow capabilities of your pump, but it will make sure that the car starts instantly, every single time. We recommend installing an inline check valve even with a brand new pump, so the tank doesn't need to be dropped again a few months later.
All Quantum brand products are backed by a lifetime warranty. Quantum products that fail at any time will be replaced under warranty if it is determined that the failure was due to a defect in workmanship or material. This warranty only applies to the original customer and is non-transferable. Improper use or installation of the product voids this warranty, and Quantum is not responsible for incidental costs resulting from failure of the product. In the unlikely event that you should need to request a warranty, please contact us at with your order information and a detailed description of the problem.