Somewhat of an inconvenience but that's why it's probably cheaper than other places selling the same part Great product from holley, but these do not come with the supplied tap that's suppose to be in box for the 2 machine screws that mount the regulator to the bracket. Holley 12-804 Fuel Pressure Regulator Brand: Holley 415 ratings -11% $6614 Was: $73.94 3/8" pipe thread ports 7/32" restriction Pressure ranges from 1 to 4 PSI Includes mounting bracket Satin finish See more product details + + Total price: $115.81 Add all three to Cart These items are shipped from and sold by different sellers. So they started putting more of the low grade gas, or high grade kerosene into the gas. There is a light spring that helps push the ball against the the seat in the direction of the fuel flow. Please try again later. That was in the 1990s, so you can project to more current times and suspect we have something more sophisticated now. f9vxY"IpBQ? Could you explain a little more about how you would run the bypass? By Free shipping for many products! This Holley FPR (12-804) use to be a perfect choice to solve the "too much fuel pressure" produced by the aftermarket fuel pumps on vintage VW. I suspect as the article suggests even with all these steps you can still get the crap gas to boil if it is hot enough under the hood. TURNING THE ADJUSTMENT SCREW ALL THE WAY IN WILL RESULT IN EXCESSIVE FUEL PRESSURE . Steve_Mack_CT The Holley 12-804 is a 1 to 4 range PSI regulator. That's not to say that adding something like kersene won't help, but it can't eliminate the volatile components. ", So . In fact I can completely remove the adjusting screw and it still does not go down to 3psi. The ethyl acetate in the IMCT loosens hydrogen bonds on the gasoline making it easier to light to burn, but the "oil" - heavier hydro-carbon nature keeps the vapor point higher and flash point still low enough to give good performance. 12-804 12-500 Low-Pressure Fuel Regulator (std. Holley recommends applying PTFE paste to the NPT thread of the fittings before installation on these applications. If youre looking to dial it in accurately its not going to do it. ***The inlet pressure limitation is 7 psi. The reg takes 3/8" fittings and the gauge takes 1/8" fittings. ). This will ensure that the pump will not continue to operate after the engine is .