fuel pressure remain after engine off?

[mkIIIman089]

Hey guys, quick Q and this may seem obvious but I think better safe then sorry.

Tonight I want to tap for my FP guage and I have all the stuff i need, only thing is I want to make sure that somehow fuel pressure between the pump and FPR doesn't get trapped in under pressure. So that when I tap it fuel doesn't spray everywhere.

Thanks!

 

[IJ.]

Colin: It'll hold pressure for awhile but it eventually bleeds down.

Drop a rag over a wrench then crack a banjo to relieve it.

 

[Ckanderson]

shouldent bleed down pressure...


also not a TON of gas comes out.. its nothin to worry bout...

 

[mkIIIman089]

Okay, I figured even if it was it wouldn't be too bad like you said ck.

Thanks for the quick reply guys!

Later.

 

[mkIIIman089]

mmk, so I cracked the banjo bolt that feeds the FPD from the tank... and there was not a pound of pressure in there. I twisted it probably like 3-4 turns out and no pressure to be found.


So now, is there something wrong? Or is it supposed to bleed off within two hours of driving?

 

[jetjock]

The system should retain rest pressure after the engine is shutdown. It should drop no more than 5 psi in 10 minutes. It'll likely be gone after two hours though.

Btw, you can relieve rest pressure a couple of ways to prevent spillage. 1) Remove the fuel pump relay/resistor connector and let the engine die. 2) If you have a hand vac pump (like a MytieVac) apply 25 inches to the fuel regulator for about 45 seconds with the engine off. You should remove the gas cap too.

 

[IJ.]

Colin: As I said it WILL bleed down eventually

 

[mrnickleye]

Crack the bolt at the cold start injector. Its right up top, and the pressure will drop off in .02 tenths of a second. :biglaugh: and you won't even get squirted in the eye. :biglaugh:

 

[mkIIIman089]

Cool, thanks guys! I got my guage set up finally (been like 3 months since I bought the thing) and everything seems to be working properly. Kind of neat to see how much it actually changes just going up hills and stuff

 

[Nick M]

If it bleeds down, the check valve in the pump is bad. It should only go down a little bit.