EFI fuel supply question
Thread Starter
Melting Slicks
Joined: Mar 2002
Posts: 2,164
Likes: 7
From: Beringen
EFI fuel supply question
Recently there were some posts about a fuel sump which would be necessary to run EFI. Since I have a tank with a bladder inside, this is impossible. After some searches I found the solution and that is an accumulator, which is a tank with a connection on the bottom for feeding the high pressure EFI-pump, three on top for the fuel supply to the tank at low pressure, one for the return to the tank and one with the high pressure return from the fuel rails.
I have on question though. I would like to use my engine driven pump to provide fuel to the accumulator, but since these pumps have 3 connections, being a feed to the carb, a suction line and a return line, i ask myself what would be the best way to connected it to the accumulator.
I have on question though. I would like to use my engine driven pump to provide fuel to the accumulator, but since these pumps have 3 connections, being a feed to the carb, a suction line and a return line, i ask myself what would be the best way to connected it to the accumulator.
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
I don't understand what you are trying to do....
you do NOT use any mechanical pump for any type of EFI....not possible that I know of....
the small accumulator tank addition to my EFU car maybe happening yet, but sorta hard to find, and lately it's not so much of the problem with cornering/stopping and fuel starve .....
I going for a LT1 manifold changeout, and if I can do that, instead of the TPI transplant there now,......I will try putting the pressure regulator in back, feeding just one fuel line to up front, and using the present return line ~1/4 inch OD...for running the vacuum source to the mani......
advantage...simplicity....
and cheeeeeeep....
you do NOT use any mechanical pump for any type of EFI....not possible that I know of....
the small accumulator tank addition to my EFU car maybe happening yet, but sorta hard to find, and lately it's not so much of the problem with cornering/stopping and fuel starve .....
I going for a LT1 manifold changeout, and if I can do that, instead of the TPI transplant there now,......I will try putting the pressure regulator in back, feeding just one fuel line to up front, and using the present return line ~1/4 inch OD...for running the vacuum source to the mani......
advantage...simplicity....
and cheeeeeeep....
Thread Starter
Melting Slicks
Joined: Mar 2002
Posts: 2,164
Likes: 7
From: Beringen
Easy enough, with cornering, acceleration, and braking, the fuel pickup in the tank would be exposed to air at times. To prevent the fuel system from starving, you will have to use either a sump or an accumulator.
What I want to to is use an accumulator and feed it with my mechanical pump...
What I want to to is use an accumulator and feed it with my mechanical pump...
Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
82 with the CFI uses the same tank you have with no sump. Are you having problems or just think you might? I am using an external pump with a 69 tank and no sump or accumulator on my TPI conversion and I have never had any problems sucking air. If I was you, I'd get an 82 sending unit and an LT1 pump and just use that in your existing tank.
Race Director
Joined: Nov 1999
Posts: 10,643
Likes: 8
From: Foxfield CO 1970 Convertible
I built my own "accumulator" or sump. I don't want to burn up a $300 pump if the suction side goes dry. I think you would be asking for trouble by including a mechanical pump in the system. Why can't your accumulator fill with gravity?
FWIW, I have heard of systems with two electric pumps, but they seem like so much extra complexity.
FWIW, I have heard of systems with two electric pumps, but they seem like so much extra complexity.
