The sard should only work one way - the internal spring & diaphram are setup to have high-pressure (e.g. rail pressure) on one side only. Going the other way, it'll be fighting the wrong way against the spring pressure and changes in manifold vacuum will have the reverse effect (when manifold vacuum is higher you need less fuel pressure, running backwards the regulator will do the opposite).
Can you get some phone pics of the setup and post them - something sounds very wrong.
Going back to your original post:
correct- the fuel pressure will vary manifold vacuum varies as the engine is at various load and rpm states - this is normal.fuel pressure goes up and down
By chance, was your car originally tuned with a fixed-pressure fuel supply?
and this is how you would setup a carbi supply where you want a continuous and stable fuel supply (tho usually only at a few psi). See question above.But when I hooked it up before injectors its run without any problem
yes, the gauge - if setup like you describe is on the return line to the tank and effectively open and not holding any pressurebut pressure gauge in FPR won't display anything, gauge in end of fuel rail display around 38psi.
This is how mine (and just about any other Sard regulator I've seen) was setup on my old car and is setup the same on the GT4:
note: the fuel in port and the pressure gauge port open into the same space in the regulator. You can check this by blowing into one of those ports and putting your finger over the other port. It will only come out the bottom port when you overcome (e.g. can blow ~38psi) the regulator spring.
Bookmarks