73 Challenger getting Edelbrock E-Street EFI with fuel sump system

[YellowThumper]

I like your positioning of the wiring pass through.  It is a clean setup. Have to make a decision soon on my conversion.

Mike

[JoeGrapes]

Thanks. You can't see the pass thru from the inside. The cutout is above the carpet and in a spot just under the heater box and the wiring runs up thru a space in the heater box and over to the back of the glove box. There is plenty of room under the dash for all the wiring. I can still use the glove box and the relays, fuses and ECU are easy to get at if I need to.

[ShelbyDogg]

71340RT was driving, the plastic fitting on his Edelbrock sump would pop out, then the car would die.

We used a hose clamp band to hold it down to get through the Mopar Nats. On the way home, I was doing my in-head troubleshooting and realized what he had done.

1. He is using a vented cap that allows air in (one way) You don't want it to dump fuel out, especially on a Challenger. A vented cap keeps the tank from collapsing slowly as your pump sucks it dry. You can test yours by being able to suck air in the back of the gas cap, but you can't blow through it.
2. His tank and expansion tank cant vent anywhere except to the front line to the charcoal canister.
3. He junked the canister and used that line as an EFI return line to the tank.

He filled up, cool gas expands, he got stuck in traffic, system popped the plastic plug, car died.

I told him to use a 70 Challenger filler tube to dump the fuel to the ground. (dangerous but works)
A better fix would be to reinstall the canister and run a new return line.

Just a heads up because he keeps blaming Edelbrock EFI when he has problems.  Did it when his new ignition failed too.

[brads70]

71340RT was driving, the plastic fitting on his Edelbrock sump would pop out, then the car would die.

We used a hose clamp band to hold it down to get through the Mopar Nats. On the way home, I was doing my in-head troubleshooting and realized what he had done.

1. He is using a vented cap that allows air in (one way) You don't want it to dump fuel out, especially on a Challenger. A vented cap keeps the tank from collapsing slowly as your pump sucks it dry. You can test yours by being able to suck air in the back of the gas cap, but you can't blow through it.
2. His tank and expansion tank cant vent anywhere except to the front line to the charcoal canister.
3. He junked the canister and used that line as an EFI return line to the tank.

He filled up, cool gas expands, he got stuck in traffic, system popped the plastic plug, car died.

I told him to use a 70 Challenger filler tube to dump the fuel to the ground. (dangerous but works)
A better fix would be to reinstall the canister and run a new return line.

Just a heads up because he keeps blaming Edelbrock EFI when he has problems.  Did it when his new ignition failed too.

What if he simply ran without the gas cap ( or loose)  as a temporary measure?

[ShelbyDogg]

Dumps gas on your paint, but would work.

[JoeGrapes]

Hmmm, good tip. When I set the system up, until I could decide how I wanted to run the vent line, I just ran the vent hose straight down and cut it off about at where the bottom of the radiator is. I kinda forgot all about it, but never had any fuel drip out and it's been running great. I really should do something more permanent. 

[ShelbyDogg]

return line should be in the tank  in case it vents. Don't the instructions say that? I don't have one to read up on.

[JoeGrapes]

Yeah it does. what i did was suppose to be temporary to see how the system was working.  I guess the vent line will be next on my list.

[JoeGrapes]

The Edelbrock sump is a returnless fuel system. The vent is just a vent not a fuel return line. If i run the vent line back to the return fitting on the sending unit i'm afraid that when the tank is full the fuel will run back up the vent line and keep the sump from venting much like a sink trap. I think i'll run the vent line to the vent tube on the right side of the tank and maybe connect it to the metal vent tube running up in the trunk but make the fitting higher than the fuel tank so i dont get any fuel backing up in the line.

[YellowThumper]

I removed the vent line canister on my 74.
Turbo room 
Kept the open end up high but routed it to the outside of fender well. Added a 90 deg bend so it points downward and added a cheap gas filter to keep the debris out. Out of sight and still breaths.

Mike

[JoeGrapes]

Right where I have the sump mounted there is a square hole in the frame rail. I think I'll get a cheap fuel filter like you did and run the vent hose into the hole and down the frame rail a little. That's pretty much the way gas tank vent is run.

[YellowThumper]

Right where I have the sump mounted there is a square hole in the frame rail. I think I'll get a cheap fuel filter like you did and run the vent hose into the hole and down the frame rail a little. That's pretty much the way gas tank vent is run.

That is what I originally did but my ana! retentive kicked in and did not like it. That hole is an access panel for front end alignment.  If you look down along the frame rail just back of the engine compartment there is a splice in the metal line with a normal rubber fuel line. I separated it there, bent a new one and ran it up and over. All is out of the line of sight.
If you want I can post pics of what I did.

Mike.

[JoeGrapes]

Another thought was tossed my way. If the vent hose is not run back to the tank and if the float in the sump sticks then the gas will have no place to go but outside the car. 

[71340RT]

Edelbrock told me there is a new smaller sump coming out this fall. They also said to just run the vent down to the ground and not to the tank which is a change from what they told me when I installed the sump kit. I have had other issues with my E-street EFI and hope Edelbrock gets me fixed up soon. I had installed a fuel pressure regulator but would not help if the gas tank built pressure and went into the sump causing the electrical plug to push out. I still want to move my ECU into the passenger compartment after I fix my other issues.

[JoeGrapes]

Yes, Edelbrock just told me a lot of people vent the sump to the open air. As long as you vent it away from any high heat they are fine with it. I have a small motorcycle crankcase breather that has a nipple that's 3/8" ID so it will fit the vent hose perfectly. I have the sump mounted where the washer bottle was and on the frame just below the sump is a hole that runs thru so I'm going to run the vent hose in the hole thru the frame and connect the breather to the hose where it comes out the bottom of the frame. If it does drip fuel it just drip on the ground. The fuel take does have a single vent tube that goes up into the trunk and back down into the frame so the stock fuel system is vented.
The EFI has been working fine with no vent problems and never any sign fuel coming out the vent hose. Switching from the orange MP box to the FBO system made a big difference. Relocating all the E-Street wiring and hardware to the cabin sure did clean up the firewall and was an easy things to do. I did lay out the EFI wiring harness and rearranged the wires so they all ended up where I mounted ECU and relays which made for a much cleaner install.