How long should Fuel pressure hold?

[litz]

Hi,

Ripped the O-ring on the pressure regulator when trying to reinstall it yesterday. Put one in I got from Home Depot, auto supply places were closed.

No visable leaks on the regulator to fuel rail or fuel line to regulator connection. However, after sitting overnight, pressure drops back down to 0 from 42LBs, is this normal? I do not remember if it did this before since I never paid any attention to it. Guage is rail mounted under the hood.

If the drop is normal, cool, if not then I will be replacing the $0.24 rubber o-ring with the $3.00 kit from PEP-Boys later today.

Appreciate the feedback ans I do not want a fuel fire while driving.

 

[SuperSix]

Wouldn't alarm me...

Mine does that sometimes over night..

 

[litz]

Great glad to hear it. I was not sure. since the first time when I ripped the O-Ring I had fuel spraying everywhere, then got it back together with plumbing O-Ring, and seemed fine until this morning, 4:30am leaving for work and look under the hood to see no pressure.

I thought it was a sealed system so the only way for pressure to drop was if there was a leak or if pump was letting fuel back into tank.

glad it is normal.

 

[d0n_3d]

with brand new 50 lb injectors and new o-rings my fuel pressure only stays for about 2 hours...so it's normal

btw when i had to reinstall my fpr i ripped about 10 of those stupid o-rings...it's a real PITA hooking a fpr back up!

 

[SuperSix]

I'm happy to know you can get replacements @ Home Depot!

Did they fit OK? Where can you get "true" replacements?

 

[litz]

I got the O-Ring in the plumbing department, $0.24 each. I do not remember the size, I just took the regulator in with me since I could not find the original O-Ring, it fell onto the intake manifold and could not get it.

 

[Warp6]

not sure how well those o-rings hold up to gas. Viton (red) is the stuff you need for fuel connections. Not saying the ones you have will fail, but is it worth the gamble?

 

[SuperSix]

Originally posted by Warp6
not sure how well those o-rings hold up to gas. Viton (red) is the stuff you need for fuel connections. Not saying the ones you have will fail, but is it worth the gamble?

THat what I was wondering.. Whether they will hold up to the gas..

 

[litz]

I was/am concerned about them holding up to gas as well, but all auto parts places were closed Sunday night, so it was HOME DEPOT or nothing. Will be switching them out for the proper ones tomorrow.

 

[SuperSix]

Originally posted by pdq4av6
The o-rings for the FPR going to the fuel rail and the fuel injectors are the same size, and are available at AUTO ZONE, just ask for the fuel injector seal kit I believe it was $9.00. GM wanted $23.00 for the kit.

I need the teeny-tiny ones that go on the fuel supply line to regulator..

 

[Warp6]

Auto Zone in the HELP section. All the stuff is in the red packages. Look for the reddish colored o-ring kit. $6 something if I remember correctly.

 

[S10xGN]

Originally posted by d0n_3d
with brand new 50 lb injectors and new o-rings my fuel pressure only stays for about 2 hours...so it's normal

Glad to hear that! My 50's are ditto, the old red stripes held 20 PSI for weeks!

 

[soonergn]

1-2 seconds? That's way too fast. Sounds like you may have a problem somewhere. How well does the car run?

 

[soonergn]

Well, the fuel can only get out 3 ways, assuming you have no external leaks. It would be getting past one or more of the injectors and into the cylinders, the regulator and going back into the tank, or back thru the fuel pump and into the tank.

 

[soonergn]

That would only stop it if it is leaking thru the fuel pump. I don't think it should be leaking that fast thru any point but I don't have any experience with any of the fuel parts you've listed. It could be possible that it's not unusual for the pump or regulator to bleed down quickly but not the injectors I wouldn't think. You could call the makers of the pump and reg to find out and see what they think. Or someone with knowledge of your particular parts could chime in. If there's no problem with starting the car or the way it runs then maybe it's not even a problem.

 

[Bonden]

Had the same problem with a quick loss of fuel pressure. Turned out it was a bad/or missing check valve in the pump. Develped into a hard starting situation but that was the pump itself. replaced pump - no more problem. Its either a bad check valve in the pump, bad f/p regulator or bleeding by an injector. If its bleeding by an injector, it will wash the cylinder walls - big problems can result. Check at gnttype.org. There is a thread in there about this issue.