Fuel Pressure
04-28-2009 | 04:56 PM
#12
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Joined: Sep 2003
Posts: 382
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From: Bishop,CA
Just wanted to let everyone know what i found to be my fuel pressure problem.
The pumps were tapped into the ignition wires from the key switch to the MSD box. I installed relays with a direct hot and ground to the battries and no more loss in pressure. The previous owner must not have been aware of the volt drop this caused to the pumps. I had to do a fair amount of digging to find this, but all is good now.
Thanks again to everyone who replyed with information.
The pumps were tapped into the ignition wires from the key switch to the MSD box. I installed relays with a direct hot and ground to the battries and no more loss in pressure. The previous owner must not have been aware of the volt drop this caused to the pumps. I had to do a fair amount of digging to find this, but all is good now.
Thanks again to everyone who replyed with information.
04-29-2009 | 12:15 PM
#13
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Joined: Nov 2001
Posts: 3,393
Likes: 6
From: IBX
I have similar fuel pressure readings on my carbed 454.
Can anyone describe how the low psi numbers translate to performance?
Does it just run out of power on the top end smoothly? or does it sputter, break up and run like crap?
Sorry for the sidetrack, but this seems related.
Can anyone describe how the low psi numbers translate to performance?
Does it just run out of power on the top end smoothly? or does it sputter, break up and run like crap?
Sorry for the sidetrack, but this seems related.
04-30-2009 | 06:50 PM
#14
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Joined: Mar 2004
Posts: 114
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From: DETROIT MI
fuel pressure
BLEFEVER The fuel pump that you have was made by S-X PERFORMANCE for edelbrock.It is the same as a 18205.
This pump is rated for a engine that max h.p. is 480hp.
If you engine is less than that you probily have to small of a fuel pick up line. At 5lbs psi this pump delivers 1.16gpm at 6psi it is .83 gpm. at 3psi flow is 1.66 gpm. A 500hp engine requires only .70 gpm at wot. so when you pressure drops at throttle my best guess is that the pump is not getting fuel or you hve more hp than 480.
This pump is rated for a engine that max h.p. is 480hp.
If you engine is less than that you probily have to small of a fuel pick up line. At 5lbs psi this pump delivers 1.16gpm at 6psi it is .83 gpm. at 3psi flow is 1.66 gpm. A 500hp engine requires only .70 gpm at wot. so when you pressure drops at throttle my best guess is that the pump is not getting fuel or you hve more hp than 480.
05-01-2009 | 12:10 AM
#15
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Joined: Sep 2003
Posts: 382
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From: Bishop,CA
Fixed
Just wanted to let everyone know what i found to be my fuel pressure problem.
The pumps were tapped into the ignition wires from the key switch to the MSD box. I installed relays with a direct hot and ground to the battries and no more loss in pressure. The previous owner must not have been aware of the volt drop this caused to the pumps. I had to do a fair amount of digging to find this, but all is good now.
Thanks again to everyone who replyed with information.
The pumps were tapped into the ignition wires from the key switch to the MSD box. I installed relays with a direct hot and ground to the battries and no more loss in pressure. The previous owner must not have been aware of the volt drop this caused to the pumps. I had to do a fair amount of digging to find this, but all is good now.
Thanks again to everyone who replyed with information.
Heres what I found, see above. Motors are 375hp. All is good now. Thanks for the help.
