I finally got my fuel pump to work, turned out to be the fuse under the dash. looked fine but no worky. so now I am trying to get some fuel pressure happening in the new system, but no luck yet. I turn the key on, hear the pump prime, and quickly check the fuel pressure gauge, and see it quickly returning to zero from an unknown pressure. here are some questions:

1) Regarding the Aeromotive FPR, how long after the fuel pump shuts off should you see pressure in the gauge? for me it's 1.5-2 seconds, and that doesn't sound right to me.

2) on the set screw (pressure adjustment on top of the FPR unit) about how far screwed in should it be to get roughly 35 psi? I have mine almost flush with the lock nut right now, so can't increase pressure much more.

I have the KG parts secondary fuel rail also, and I'm not sure about the fittings that go into it. They are the type where the threads crush down to form a seal when you install them, and they say to not use thread sealant. I went about as tight as I dared before they felt like they might strip out, but that wasn't very many turns in. has anyone had problems with these before? the only thing that could be a leak came from these fittings. nothing real noticeable, but a thin layer of fuel was on the ends of the rail. I really don't think it's enough of a leak to cause me to lose fuel pressure that fast.

let me know your thoughts, thanks.

 

That has to do with what pump you are running, not the FPR. Some pumps will immediately drop pressure, some will hold it...

We can't "tell you" how far to set the screw. You will need to ensure there are no leaks, get the car to start and go out and set the FPR with the car running. Make sure to set the FPR with the vacuum hoe NOT attached. when you attach it after setting, you will note the pressure to drop from what you just set. This is normal.


The threads on the rail itself are NPT and should use sealant. the AN fittings do not. Being NPT threads, you are not going to get more than a few "turns" out of them before you should not tighten any more or benefit from playing "He-Man" and getting more turns.

The slight leak can be cause by not using sealant in reply above. Your leak is not causing the pressure drop when turned off. Refer to the answer to your 1) question.

-KG

 

^thanks much.

to people running a walbro pump, have you noticed if it holds pressure or not after shut off?

 

^ If I recall correctly the Walbro I used to run back in the day held pressure after shutoff. You might want to pull your pump assembly and check the pump outlet to make sure its nice and snug. I also believe there is a small plastic washer/o-ring that is mounted to the top of the pump out let to insure a good seal. If the seal isn't good your fuel pressure will bleed off rapidly, thats bad thing when under boost.

 

^ good idea. thanks.