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How long should fuel pressure be maintained after shutdown?

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Old 10-05-2002, 05:43 PM
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How long should fuel pressure be maintained after shutdown?

Right in the title. Just want to know how long after I shut off the should the fuel pressure stay up. Is it supposed to be indefinite or does it blled down after a 1/2 hour or so?
Old 10-05-2002, 11:56 PM
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well, it depends. If the drainback valve in the fuel pump is functional, and you don't have any sort of leaks, it should last quite a while. Could take up to a couple hours for the pressure to bleed off completely.

But, if you're lucky like me, your fuel pump drainback valve doesn't work, and the pressure bleeds off immediately. I'm on my 2nd fuel pump and it's doing it now too.
Old 10-06-2002, 08:29 AM
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I went from stock to Holley and had nothing but problems with it. So I went back to a carter last year. My pressure holds 40 some pounds for about an hour then slowly bleeds off. Is that a problem?
Old 10-06-2002, 08:57 AM
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The Holley 255 lph pump has no valve. Mine loses pressure in 5 seconds. No problems other than slightly extended crank times on startup.
Old 10-06-2002, 03:15 PM
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Originally posted by Ricktpi
The Holley 255 lph pump has no valve. Mine loses pressure in 5 seconds. No problems other than slightly extended crank times on startup.
i have a Walpro 255,which is the same as the Holly 255(look on the side of your Holly pump it'll say Walpro )and it'll hold pressure for a few seconds but i don't have any extended crank time
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