Overpressure Regulator Kit 85 psi - Mopar - GM - Ford - FPCM

When you have a non-OEM fuel pump running via a pulse-width-modulation (PWM) controller such as a factory Fuel Pump Control Module (FPCM) or an aftermarket one like VaporWorx, your fuel system can build up excess fuel pressure since there is no regulator. This excess pressure can rise so high, that it could prevent the injectors from opening when commanded. When this happens, you have a no start condition.  Common appliations: Hellcat / Hellcrate with factory type controller; Chevrolet Performance LT1 / LT4 / LT5 with FPCM. Factory fuel pump modules have this feature built in, so there is no issue. This specifically relates to most all aftermarket / Walbro / Aeromotive (and more) fuel pumps. This regulator is pre-set to 85psi which is higher than your FPCM will command. In most cases the regulator will only return fuel after the engine is off and vapor expansion begins to increase fuel pressure.  The regulator body has a 6AN return built in, and a 6AN ORB to 6AN Male adapter is included for the inlet, as well as a 6AN ORB plug and 1/8npt plug. These plugs can be removed and sensors added to them, since they will see full fuel pressure.  How to plumb it in: This regulator requires a few extra parts for installation.  First, you need a check valve. I usually put this before your inline fuel filter. It can be installed anywhere in the feed line, before the overpressure regulator.  The regulator will need a fuel pressure feed going to it, which means you need a tee (T) fitting somewhere inline, after the check valve. We usually attach one to the other end of the inline fuel filter.  A line will run from the T fitting to the SIDE of the regulator, 6AN size.  The bottom of the regulator is 6AN and you will run this directly to the return port on the fuel tank.  Location: Closest to the tank for a short return line works great, but it can be mounted anywhere as long as you follow the plumbing route.