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LB9 fuel system bleed off

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Old Jun 15, 2015 | 10:04 PM
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happyhapka
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LB9 fuel system bleed off
So one thing I noticed when I checked my fuel pressure is that it bleeds off really fast.. What would cause it to bleed off so fast..... My pressure while idle is 44psi and with it unhooked it was 49-50psi... But would not hold during priming before I start it...

It would take. About or less than 5 seconds to bleed off to 0 I'm not sure why.
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Old Jun 16, 2015 | 06:57 AM
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Re: LB9 fuel system bleed off
Originally Posted by happyhapka
So one thing I noticed when I checked my fuel pressure is that it bleeds off really fast.. What would cause it to bleed off so fast..... My pressure while idle is 44psi and with it unhooked it was 49-50psi... But would not hold during priming before I start it...

It would take. About or less than 5 seconds to bleed off to 0 I'm not sure why.
Outside of an outright leak , which you would see and smell the escaping fuel , there are three things that cause this .

#1 Leaking injector(s)

#2 leaking fuel pressure regulator

#3 leaking check valve built into the fuel pump
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Old Jun 16, 2015 | 07:28 AM
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Re: LB9 fuel system bleed off
"#3 leaking check valve built into the fuel pump"

I second that!
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Old Jun 16, 2015 | 09:27 AM
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happyhapka
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Joined: Jun 2014
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From: Montana
Car: 1986 Trans AM WS6
Engine: 383 Vortec TPI, PUTS SMILES ON FACE
Transmission: PATC LVL 3 Raptor Transmission
Axle/Gears: 3.27 POSI 9 BOLT
Re: LB9 fuel system bleed off
OK so either its my inj.. Or fuel pump... Hmmm. OK thank you guys... You all are awsome
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Old Jun 16, 2015 | 10:06 AM
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happyhapka
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Joined: Jun 2014
Posts: 393
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From: Montana
Car: 1986 Trans AM WS6
Engine: 383 Vortec TPI, PUTS SMILES ON FACE
Transmission: PATC LVL 3 Raptor Transmission
Axle/Gears: 3.27 POSI 9 BOLT
Re: LB9 fuel system bleed off
One more question how long should they hold pressure... How fast is it suppose to bleed off
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