sam

Mine is reading at 32-35 psi when at idle and reving. I know it could be as low as 30 compared to normal 40 and should be fine.

HOWEVER. I have 3" hooker cat back system. Soon to put high flow cat. Also I have the edelbrock TES headers along with the slp runners and edelbrock tpi base intake.

So am i loosing hp due to fule pressure level? If so what can i expect to get hp and torque wise if i get an after market fuel pressure regulator and up it to about 48 PSI ?

I am certain I will get lots of feedback right?!?


Sam

rgarcia63

Fuel pressure is inversely proportional to vacuum.
As vacuum decreases fuel pressure increases, that's why it's highest when the engine is off, or at WOT.
If your losing pressure as you go to WOT, you either have a bad regulator, or fuel pump.
Once you solve this problem set the static fuel pressure at 43psi with no vacuum.
Reconnect the vacuum, and bump the pressure up 2psi at a time until there's no increase in power.

sam

thanks rgarcia63,

I was not losing pressure as the engine got reved up.. so must be regulator?


Also am i losing hp because of this?

doc

Because of the vacuum situation, you are supposed to check the fuel pressure with the engine warmed up and running at idle with the fuel pressure vacuum line pulled & plugged. On my previous stock car, I had 44 psi with this method. With the vacuum line hooked up, the fuel pressure was about 36 psi.

With full mods, I am now running 52 psi / 44 psi.

I think your fuel pressure is a bit too low. IMO.

Red Devil

Only way to quantify any 'loss' of power is at the track or on the dyno. Have you observed the pressure readings as mentioned above?

sam

Thanks,

well mine was tested with the vaccum line hooked up. and it read 32 then when reved it would jump to 35-36 then steady at 32 again but now at higher revs.

So if i unplug and plug the fuel pressure regulator vaccum i will increase the pressure? Or should i buy an adjustable pressure regulator?

kevinc

Disconnecting the vacuum ref would only give you the same fuel pressure as you get at WOT anyway.

If you want more pressure than that, it's time for an adjustable regulator.

And the only real way to know if you need more fuel delivery is with a wideband O2 sensor and some street or dyno time. Adding fuel to an engine that doesn't need it reduces power production...you could spend the $$ and end up slower.