Fuel presure valve - line pressures etc
Thread Starter
Drifting
Joined: Sep 2004
Posts: 1,638
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Fuel presure valve - line pressures etc
So let me see if I am reading the FSM correctly - the fuel pressure regulator works by "releasing" the extra pressure from the pump - in other words - it's on the tail end of the fuel rails allowing excess pressure to "escape" is that correct?
I can't seem to find a local 16mm X 1.5 saginaw fitting to go on the stock fuel lines. I ordered 2 of them from Summitt - they sent me 2 - 1 correct - 1 the wrong size, and I can't find a local supplier that carries em. One option would be to take the return line and hillbilly rig the factory "to rail" setup - cut it off and hoseclamp fuel line to that - but I don't want to do it if the return line is under big pressure! anyone know what pressures are on the fuel return line?
Oh yah - we will do it right - but we need to have it up and running immediately for this weekends speed trials - so for now I need solutions that are immediate, and keep the 88 safe and running!
Carl Johansson
I can't seem to find a local 16mm X 1.5 saginaw fitting to go on the stock fuel lines. I ordered 2 of them from Summitt - they sent me 2 - 1 correct - 1 the wrong size, and I can't find a local supplier that carries em. One option would be to take the return line and hillbilly rig the factory "to rail" setup - cut it off and hoseclamp fuel line to that - but I don't want to do it if the return line is under big pressure! anyone know what pressures are on the fuel return line?
Oh yah - we will do it right - but we need to have it up and running immediately for this weekends speed trials - so for now I need solutions that are immediate, and keep the 88 safe and running!
Carl Johansson
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Originally Posted by Carl Johansson
So let me see if I am reading the FSM correctly - the fuel pressure regulator works by "releasing" the extra pressure from the pump - in other words - it's on the tail end of the fuel rails allowing excess pressure to "escape" is that correct?
RACE ON!!!
PS. As the car speed or RPMs increase, the return line pressure will drop. The electric pump puts out a constant volume. As more fuel is consumed, there is less volume, hence, less pressure in the return line.
Last edited by CFI-EFI; Jul 12, 2007 at 11:51 AM. Reason: PS.
Le Mans Master
Joined: Jan 2002
Posts: 9,036
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From: Edmonton AB
This thread is a spin-off of an earlier thread
HSR Intake Install - questions!
I responded to part of this post there and discussion has continued
in it to keep questions and answers together in one spot for Carl's project.
Thanks,
Ken R.
.
HSR Intake Install - questions!
I responded to part of this post there and discussion has continued
in it to keep questions and answers together in one spot for Carl's project.
Thanks,
Ken R.
.
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
The return line pressure has to be pretty small, even at idle, can't be more than a few psi, whatever the pressure drop in the hard line is. I'm not aware of any restrictions leading back to the tank unless it's got one of those return line filters in place.
Keep in mind the rubber lines at the tank are just clamped in place, even the supply line, where pressure is the highest. I wouldn't fret about using clamps and barbed/flared lines as long as the hoses are not able to move much.
Don't bother with the Summit catalog, it sucks. I use the mfr catalogs to find the p/n's then order from Summit.
http://www.holley.com/division/Earls.asp
Keep in mind the rubber lines at the tank are just clamped in place, even the supply line, where pressure is the highest. I wouldn't fret about using clamps and barbed/flared lines as long as the hoses are not able to move much.
Don't bother with the Summit catalog, it sucks. I use the mfr catalogs to find the p/n's then order from Summit.
http://www.holley.com/division/Earls.asp
Last edited by CentralCoaster; Jul 12, 2007 at 12:28 PM.
