Electric fuel pumps with variable rates:

[vandelay industries]

1) For electric fuel pumps that are rated at, say 4-7 psi, such as the Holley mighty max which is one that i'm interested in, how does the pump "know" when to pump 7 and when to pump 4 etc.? Or do certain conditions cause the pump to put out more pressure or less, i.e., empty bowl etc.?

2) If a regulator is used, would this put more stress on the pump?
a) i can run a return line as it already exists.

i'm running a quadrajet that calls for 6.5 psi max.

This will be my first electric pump as the block is a newer 4.3 vortec type block with no mechanical pump provisions.

 

[RootBreaker]

i can tell you dont go with the crap from autozone. I did and it is bad... yeah it was cheap.. but why do twice..

Im interested in what others say.. i have a holley truck avenger the aluminum one (loving it but have only driven truck home. needs fuel pump, ps pump and brakes bled)...

 

[Blue85]

The pressure depends on the flow and amount of restriction. The pump is not smart and doesn't physically change what it's doing - the pressure is the result of the specific conditions it's running in. For FI, that's primarily what the fuel pressure regulator is set at. In a carb, it will depend on whether the needle is open or closed, voltage to the pump, etc.

 

[RootBreaker]

The pressure depends on the flow and amount of restriction. The pump is not smart and doesn't physically change what it's doing - the pressure is the result of the specific conditions it's running in. For FI, that's primarily what the fuel pressure regulator is set at. In a carb, it will depend on whether the needle is open or closed, voltage to the pump, etc.

I did read that yesterday... they said they recommend use of a relay too for the voltage part.

 

[RootBreaker]

here is the article.... fyi..

http://www.how-to-build-hotrods.com/electric-fuel-pump.html

 

[Hoss7979]

Yep run a relay and a return style regulator. That's what I switched to for my bbc....
http://www.summitracing.com/parts/qft-30-900/overview/

 

[vandelay industries]

i'm looking at pumps like the facet cube or Holley mighty mite, because i think those pumps can pull....a little. They are listed as self-priming anyways. It's not real easy in my case to put the pump real close to the tank (this is a truck so it's saddle mount vs. rear mount) and i don't feel like dropping the tank to get to the sender unit/module thing with the 3 outlets which would make it easier to get the pump close to the tank. But will do this if necessary.

i can, however, get it about 30-32" away from the tank and below fuel level.

 

[Hoss7979]

That'll be ok distance, I run a summit pump & haven't had any issues w/ it @ all. Here's my setup, it about the same distance your talking about....

 

[nvrenuf]

While shopping for pumps, take the noise level in to consideration. I used to run a Holley "blue" pump and it was LOUD AS HELL.

Edit: I actually ran 2 different blue pumps and the sound level was the same.

 

[RootBreaker]

i'm looking at pumps like the facet cube or Holley mighty mite, because i think those pumps can pull....a little. They are listed as self-priming anyways. It's not real easy in my case to put the pump real close to the tank (this is a truck so it's saddle mount vs. rear mount) and i don't feel like dropping the tank to get to the sender unit/module thing with the 3 outlets which would make it easier to get the pump close to the tank. But will do this if necessary.

i can, however, get it about 30-32" away from the tank and below fuel level.

i have a el autozone cheapo mounted to my frame with 2 saddle bag tanks... and it is right before the solenoid. i only bolted 1 bolt so it vibrates and chatters on the fame... LOL that way I know it is working...

but im going to go redneck style and use a pump I have wanted too for a long time. hopefully get it on friday. it is a boat pump and is totally round. Not sure how I am going to mount it yet but for now it is just getting it plugged in. and this is right next to one of my mufflers!

 

[Hoss7979]

Just mount it as close to the tank as you can and keep it away from exhaust and such. If it calls for 6.5 max and you have a 7psi pump I wouldn't be to worried about the extra .5. But I would run a regulator and a gauge just to make sure your getting the correct psi.....ie making sure its giving you what you need. I would actually spring for this one if your gonna get one, it's a little extra but it has more GPH.....
http://www.summitracing.com/parts/sum-g3136-1/overview/

 

[85 Jimmy]

Or you can get a tank, sender, and fuel pump from a TBI truck/blazer and run an in-tank pump.

 

[RootBreaker]

Or you can get a tank, sender, and fuel pump from a TBI truck/blazer and run an in-tank pump.

so 2 for dual tank setups... and how does one then run the dual tank solenoid?

 

[85 Jimmy]

I don't know anything about the dual tank setups. Maybe someone else can chime in on that.

OP, is this in a dual tank truck, blazer, etc?

 

[vandelay industries]

I don't know anything about the dual tank setups. Maybe someone else can chime in on that.

OP, is this in a dual tank truck, blazer, etc?

It's a single tank (driver's side) truck. i am not ruling out adding a second tank if the original plan doesn't work. In this case i will just run the second tank and not worry about working in the dual tank function.

 

[skunked]

check out @Kay86K5 crew cab build, he just installed a couple in-tank pumps in his saddle tanks.

 

[dyeager535]

It's a single tank (driver's side) truck. i am not ruling out adding a second tank if the original plan doesn't work. In this case i will just run the second tank and not worry about working in the dual tank function.

I worked it out previous, should be able to run dual tanks with no switch/solenoid and one pump. As long as you don't require emissions.

Takes some thought, but works in practice.

 

[RootBreaker]

well ill be able to give you thoughts on this one... oh and waytekwire.com pieces for the waterproof connector. I stopped hacking things...

20160520_101253 by Jeffrey Riggs, on Flickr

 

[vandelay industries]

well ill be able to give you thoughts on this one... oh and waytekwire.com pieces for the waterproof connector. I stopped hacking things...

20160520_101253 by Jeffrey Riggs, on Flickr

This is actually one of the pumps i'm looking at. This cube also the holley mighty mite and equivalents, which look to be maybe the same as the cube but in a different package? Also facet has a canister type pump(don't know part# offhand) but it can supposedly lift 50" which would take care my mounting "problem."

 

[RootBreaker]

well ill be able to give you thoughts on this one... oh and waytekwire.com pieces for the waterproof connector. I stopped hacking things...

20160520_101253 by Jeffrey Riggs, on Flickr

wow I never gave thoughts... well it works great. it does what it is supposed to do but I didn't bolt it to the frame right. I just put 1 bolt in so it chattered on my frame. Did what it is supposed to do and supply fuel just fine.

I have taken it out as I went with a 1987 chevy saddle tank with bladder and 1987 float assembly with in tank pump.

These cost $60ish new... mine is perfectly fine and I'm selling it.. of course mine sat on the frame next to the exhaust and the sticker is gone, especially since I swamped the truck in peanut butter mud!!!!

but if anyone wants it.. $40 shipped and ill throw the other side of the plug in...