Got a pressure gauge put on the fuel rail... was at 60psi!!

Well, dropped it down to 41 with vacuum line on, 45 with line off BUT!!

If you goose the throttle... the freakin pressure drops? If you turn the car off... pressure drops?

I can't figure out why the pressure goes from 42-43 (idle) to 35-37 (little rev)? That's with no load on motor

 

Sounds like dirt in the check valve if you have a new pump in it.

 

It's a brand new pump... what check valve? Where?

 

When was it at 60psi? Was that right at startup or something? The other #s sound fine to me, but Im no pro.

BTW, Im copying your engine, pretty much. VRE is building the 4 bolt forged shortblock now, and Lloyd will have a set of heads to port soon Im trying to go as agressive with everything as possible though, as its not a daily driver, so we'll see how our #s compare. I will then spray a 200 shot

 

I love the car when it runs good... it's an absolute powerhouse at every rpm.

What numbers sound good? The decrease in fuel pressure?

 

The pressure drop at rev sounds like a bad pump. Dirt in the check valve can happen if you don't wash out the tank when you put the new pump in.

 

Wash out the tank? How do you wash out the tank is you go in from the hatch? I guess that would also mean that my system losing pressure when turning the car off would be from the fuel pump too? And crummy driving conditions?

 

No one?

 

When I tested fuel pressure on a mostly stock engine, thats what happened. It decreased slightly. But you also have an aftermarket fuel pump, so maybe thats a bad sign.

 

Are you 100% sure you are using the fuel gauge right?

 

There is a wrong way to use it? I just threaded it on the schrader valve and turned the car on. What else is there to be done?

 

When you turn your car to the 'on' position and the fuel pump charges the fails and lines with fuel you SHOULD get like 42ish psi, WHEN you turn your key off, the pressure SHOULD hold at that, and if it drops it should be over time, like an hour or so, maybe more. When i had a faulty check valve in my stock pump i would charge the fuel rails by putting it to "on" and in like 30seconds it would drop to 0. I have the same walboro pump as you chris (though i got the racetronix kit, same pump though). You need to grind out the inner portion of the tank sump (has some fins in there), did that guy do that? How fast is your pressure droping from full to 0? 60ish psi is kinda high at idle no?

 

I just noticed i have high fuel pressure with vac line off(48 psi). I have a new walbro pump, whats this about drilling something out???