Quote:
Originally Posted by Kingtal0n
all it takes is 10 seconds google search
What do you think holds fuel pressure in the rail when you key off, magic?
add an external check valve is a thing
https://www.highflowfuel.com/i-23904...fuel-pump.html
walbro pump
" The normal 255 has a check valve. the high PRessure 255 which is what you need for LSx returnless fuel systems, does NOT have it. Thus, pressure bleeds off if the pump is not running."
https://www.ls1gto.com/forums/archiv.../t-323614.html
" The pump's outlet nipple has a retainer on the end of it that holds the check valve in the end of the pump."
https://autoperformanceengineering.c...tall_tips.html
"Traced it to bad check valve in the new fuel pump I installed. Mechanic verified as well that my loss of fuel pressure is because of the bad check valve."
https://z31performance.com/forum/z31...5-hp-fuel-pump
seriously lrn2internet before you make bold assumptions. All factory fuel pumps incorporate check valve as far as I know to aid in cold/re-starts.
You can run whatever fuel pressure you want (25-100psi) as long as you can tune for it properly. I run an aeromotive stealth 750hp capable pump at 33psi around town to keep stress (P/A) off the fuel system components. |
Can you please explain where you would put a check valve in a system that is designed to return fuel to the tank to make sure the pressure doesn’t drop after the pump is turned off?
Sure, a fuel pump can have a check valve on the output, but there is nothing stopping the fuel from flowing back to the tank and pressure dropping when the fuelpump is off:
Fuel tank ->fuel pump -> check valve -> fuel rail -> FPR -> fuel tank
The check valve is to make sure the fuel doesn’t reverse flow back into the pump when the pump is off. But fuel will still flow from the check valve through FPR and back into the tank, this de-pressurizing the fuel rail when the pump is off.
Pressure in the fuel rail will always drop to zero after the pump is turned off.
Let’s stop being idiots and think shit through before we believe the forums or companies the have the word “engineering” in the company name (which is illegal in most of the country unless a state certified Professional Engineer is part of the company)