Ran a 3/8 supply and return fuel system

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TrailBeast

TrailBeast

AKA Mopars4us on Youtube
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Over the weekend I replaced my sissy inline fuel pump with a Carter high volume/low pressure rotary vane electric unit mounted on the inside of the frame rail in front of the axle and level with the tank.
I also pulled the sender and drilled it for a return nipple.

Using 3/8 nylon 12 EFI hose I ran a complete new supply line and added the return line.
One thing I gotta tell ya is that you will need to insulate the lines because anywhere the lines touch the frame or body metal causes an amplification of the pump noise in the fuel.
The line literally vibrates and the nylon transmits that vibration to the car body like putting the needle on a record.

The first time I tested the new system the bare lines were following and attached to the outside of the subframe connectors and went between the front frame rails and firewall/floor metal.
I got in the car, turned the ignition on and the pump noise was so loud I just shut the key off and said OH hell no.
I'm sure it wouldn't have been near as a bad with rubber, as the nylon seemed to really transmit the noise to the car floor and body.
I went back and took it all loose then used foam pipe insulation tubing and covered the entire supply and return lines from the pump all the way to and including where they go through between the body and frame under the passenger side floorboard.
This made the pump sounds much more tolerable, and I can't hear it with the car running at all now.

The return is T'd off right at the carb inlet and follows the supply line back to the tank.
A one way flow restrictor in the return line puts my fuel pressure right a 5 lbs (should be about perfect) for a semi mild daily driver car.

I do have an A/F connected permanently in the car and you can bet I'll be watching it closely for awhile. :D
I did get a pressure regulator for it but couldn't see the point in adding it into the system if I have a max pressure of 5lbs and it would be adding another point to transmit noise to the car body unless I made rubber mounting mods to it like the pump has.
Not looking forward to those rubber grommets hardening up, so I will probably be watching for a quieter pump as time goes on.
 
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What exactly did you use for fuel line? I need to do mine and was not sure what to use.

Cley
 
89on35s said:
What exactly did you use for fuel line? I need to do mine and was not sure what to use.

Cley
Click to expand...

Hi Cley,
I used this 555-159236 | Jegs High Performance

If you want to used barbed fittings I hope you have a camp stove you can have a pan of boiling water handy, as that is about the only way you'll get the line on over the barbs
I used 11/32 rubber fuel injection hose to make the connections so fittings didn't limit the ID of the nylon line.
Using a lighter you can gently heat the end of the nylon line and it creates a rounded bead on the end, then I ran the tips of my needle nose pliers around the inside of the line as it cooled to open up a little more ID on the ends.
Basically just used the rubber line for the joints and the nylon for the long runs under the car.
 
Did you consider installing a fuelpump cut-off switch, controlled by the engine's oil pressure?
So if the engine stalls for some reason, the fuel pump is shut-off as well.
 
What part number pump did you use? 4601?
 
BigBlockMopar said:
Did you consider installing a fuelpump cut-off switch, controlled by the engine's oil pressure?
So if the engine stalls for some reason, the fuel pump is shut-off as well.
Click to expand...

I don't consider things like that much, as I even dislike neutral and/or clutch safety switches.
If it wasn't for the Wife possibly needing to drive my car some time it wouldn't have it. :D

I did let the pump run for 5 min or so without the engine running just to make sure it couldn't cause a problem though, if that counts for anything.
 
Thanks. I am not sure If I'm going braided line or what I will do. I put in a 3/8 sending unit with my new tank so I want to run 3/8 lines to the pump. I will currently be sticking with the mechanical pump.

Cley
 
Trail,
Overtime I've seen a few cars burn to the ground on Youtube where the owners had installed electric fuelpumps but no safety-devices in case a fuelline dry-rots or say a car gets in an accident and/or ends up on its side in a ditch. Besides the accident 'hassle', which might gets you trapped in the car, I *think* the last thing you would want to deal with a blazing fire consuming your car.
Remember the electric fuel pump doesn't know or care if you've just been hit by that texting boobjob in the oncoming lane. ;)
 
This is exactly why I recommend running as much hard line as possible in the fuel system. I've always thought running ten feet of rubber hose was what Chevy guys did.
 
I always preach to use an inertia switch but it mostly falls on deaf ears .



BigBlockMopar said:
Trail,
Overtime I've seen a few cars burn to the ground on Youtube where the owners had installed electric fuelpumps but no safety-devices in case a fuelline dry-rots or say a car gets in an accident and/or ends up on its side in a ditch. Besides the accident 'hassle', which might gets you trapped in the car, I *think* the last thing you would want to deal with a blazing fire consuming your car.
Remember the electric fuel pump doesn't know or care if you've just been hit by that texting boobjob in the oncoming lane. ;)
Click to expand...
 
Inertia switches are great. I think that's a good idea. Does anybody make a switch that cuts the pump off if it loses pressure from a ruptured hose? I know there are switches that cut power if oil pressure is lost.
 
RustyRatRod said:
Inertia switches are great. I think that's a good idea. Does anybody make a switch that cuts the pump off if it loses pressure from a ruptured hose? I know there are switches that cut power if oil pressure is lost.
Click to expand...

The switches I used to make the transmission fully automatic in my car is exactly that, but they are called "fuel safety cut off switches" and they are to kill a NOS system if the fuel pressure isn't there.
I used them to turn on a circuit at rising governor pressure instead of cutting the circuit on too low of a pressure.
I plan on putting an inertia switch in it next time I get to the pick a part.
Some sick part of me was hoping if something that bad happened it would take us ALL with it. :D

"Mopar takes 7 people two dogs and a bird with it on the way out"
"Story at 11"
 
I did the Tanks Inc. Tank and internal pump. 8an stainless all the way. Can't really hear the pump when it's in the tank. Best damn thing I've ever done. Well worth it. No safety switch yet...
 
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