Correct fuel pressure?
Thread Starter
Safety Car
Joined: Jan 2001
Posts: 3,569
Likes: 1
From: Hawaii
Correct fuel pressure?
I just hooked up my fuel pressure guage and am getting a whopping 4psi at idle and when the engine is revved, it drops to around 2-2.5 psi. HAHAHAHA, no wonder I am sucking at the track and at high rpms. Shouldn't it be around 7psi ? This is on my 502ci/502hp engine.
Thanks in advance
Thanks in advance
Race Director
Joined: Mar 2001
Posts: 11,322
Likes: 1
From: Living in the Hartland
Re: Correct fuel pressure? (Maurice)
Does it need a pressure regulator and do you have one? I intalled what I thought was a Holley street pump but found out it was the strip pump in a street pump box and the pump has info on it. It over powered the shut off valve in the fuel bowls and flooded the engine at idle.
Thread Starter
Safety Car
Joined: Jan 2001
Posts: 3,569
Likes: 1
From: Hawaii
Re: Correct fuel pressure? (Fevre)
The one that I got requires a fuel pressure regulator and came with it. The install looks pretty simple, I just have to get out there and do it now. I need to pick up a fuel filter to replace the one I have now. My current fuel filter has a fuel return line connected to it, but isn't a fuel pressure regulator. I am still trying to figure out how to rework everything to make it correct.
Melting Slicks
Joined: Jun 2001
Posts: 3,281
Likes: 6
From: NC USA
Re: Correct fuel pressure? (Maurice)
I run 4 - 4.5psi all of the time with my 454. I tried it higher and was running way to rich with backfiring. This was confusing since my Demon 850 manual recommends 6 - 7psi for hipo engines. I've heard you should always run a regulator with an electric for constant consistant fuel delivery. :cheers:
Thread Starter
Safety Car
Joined: Jan 2001
Posts: 3,569
Likes: 1
From: Hawaii
Re: Correct fuel pressure? (Marks69BB)
Interesting... I was playing around with my fuel pressure today by blocking off the fuel return line and that bumped the pressure to around 6.5. I was having similar issues to what you were describing... plenty backfiring when acceleratiing, as soon as I put it back, it ran great. HMMMMMMM
Racer
Joined: Mar 2001
Posts: 372
Likes: 1
From: Ellicott City MD
Re: Correct fuel pressure? (Maurice)
The Holley book says anything over 8psi will force the floats open and cause flooding. I'm having similiar pressure drop issues (although not related to the return), so I'm interested in your results. Especially at the track.
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Thread Starter
Safety Car
Joined: Jan 2001
Posts: 3,569
Likes: 1
From: Hawaii
Re: Correct fuel pressure? (Marks69BB)
I got everything installed today (regulator, new fuel pump, and filter). I set it for 4.5 psi and the difference is incredible at the higher rpms! I cannot wait to see how much diff I have in the 1/4 now that I can rev in the gears. The idle is now much smoother also for some reason. I was sitting at the stop light thinking how incredible it is that a 500hp engine can idle so smoothly. Technology rocks!