What is the Stock fuel preasure?
08-30-2004, 04:24 PM
#4
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Join Date: Nov 1998
Location: Hell was full so they sent me to NJ
Posts: 70,648
Re: What is the Stock fuel preasure?
Originally Posted by RE AND CHERYL
43psi at idle and part throttle and 5psi higher (I think) at WOT
Turn key on, do not start engine. Fuel pressure should reach 41-47psi before the pump shuts off. It should hold 40+ psi "for a while".... if it drops off significantly in a matter of seconds, or even a few minutes, there is a problem.
Start the engine. Pull the vacuum compensation line off the fuel pressure regulator. Plug up the hose. The fuel pressure should be in the range of 41-47psi to meet factory specs. The "perfect" value is 43.5psi. Put the vacuum line back on the FPR. The fuel pressure should drop proportional to intake manifold vacuum. For a stock cam, the pressure can drop anywhere from 6-8psi below what you measured without the vacuum line. With a "hotter" cam, it will drop less.
Tape the fuel pressure gauge to your windshield and make a WOT pass. At WOT, max rpm/peak HP the fuel pressure should hold within 2psi of the "no vacuum" reading.
10-02-2004, 07:34 PM
#5
Registered User
Join Date: Sep 2004
Posts: 115
Re: What is the Stock fuel preasure?
Originally Posted by Injuneer
Just curious.... why do you keep answering these questions when you really don't know what the answer is. You aren't helping people with wrong info.
Turn key on, do not start engine. Fuel pressure should reach 41-47psi before the pump shuts off. It should hold 40+ psi "for a while".... if it drops off significantly in a matter of seconds, or even a few minutes, there is a problem.
Start the engine. Pull the vacuum compensation line off the fuel pressure regulator. Plug up the hose. The fuel pressure should be in the range of 41-47psi to meet factory specs. The "perfect" value is 43.5psi. Put the vacuum line back on the FPR. The fuel pressure should drop proportional to intake manifold vacuum. For a stock cam, the pressure can drop anywhere from 6-8psi below what you measured without the vacuum line. With a "hotter" cam, it will drop less.
Tape the fuel pressure gauge to your windshield and make a WOT pass. At WOT, max rpm/peak HP the fuel pressure should hold within 2psi of the "no vacuum" reading.
Turn key on, do not start engine. Fuel pressure should reach 41-47psi before the pump shuts off. It should hold 40+ psi "for a while".... if it drops off significantly in a matter of seconds, or even a few minutes, there is a problem.
Start the engine. Pull the vacuum compensation line off the fuel pressure regulator. Plug up the hose. The fuel pressure should be in the range of 41-47psi to meet factory specs. The "perfect" value is 43.5psi. Put the vacuum line back on the FPR. The fuel pressure should drop proportional to intake manifold vacuum. For a stock cam, the pressure can drop anywhere from 6-8psi below what you measured without the vacuum line. With a "hotter" cam, it will drop less.
Tape the fuel pressure gauge to your windshield and make a WOT pass. At WOT, max rpm/peak HP the fuel pressure should hold within 2psi of the "no vacuum" reading.
10-02-2004, 10:45 PM
#6
Registered User
Join Date: Dec 1969
Location: Little Rock, AR
Posts: 27,709
Re: What is the Stock fuel preasure?
Originally Posted by JB94
Can anyone help me narrow down the phrase "for a while" in this post. 5 minutes? 10 minutes? Should it hold pressure indefinitely after the key is turned off?
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