Holley Sniper EFI and Boyds gas tank

[BIG BLOCK JIMMY]

I have been looking for days trying to find a thread on my setup, but there's always something askew with the equation.
I have a Holley Sniper EFI kit (with an external fuel pump) and a Boyds Welding gas tank (non-EFI).
I'm not asking questions about the EFI part yet. My question is on the gas tank plumbing.

The OEM tank had the following:
Filler neck, three vent lines, supply line, and two return lines.

Boyd's tank:
Filler neck, one vent, one return, one fuel feed/drain.

Jimmy has three...four vent lines.

Question is:
Do I need a vent line running back into the filler neck? Or can I install a rollover vent and be done with it?

I'm still not sure if I need a return line with the EFI setup or not, so I suppose if not I could do a rollover vent and a vented line back to the filler neck.

I have called all companies involved and I can't get any continuity out of any of them. I guess because I'm running an EFI system with a non-EFI tank. Holley did tell me that it didn't matter and I opted for the external pump just in case I had to replace it I wouldn't have to drop the tank.

[litebulblsc]

What do you plan on doing with the vent?

Are you going to run a full evap system, or are you going to just vent it out?

I ended up just running a 1/2" line to the filler neck and run a vented cap. Although that is not the correct way to do it.

I guess I never seen the way they were stock, did they come with a charcoal canister?

The fact that you are going fuel injected makes little/ no difference on how you vent your tank, so how does Boyds say to do it in a carburetor setup?

And yes, you need a return line with the Sniper setup

[BIG BLOCK JIMMY]

No, I'm not adding any charcoal canisters or evap stuff. I was going to run a vent back to the filler neck as you did. To do that I can't install the rollover vent, which I wanted. I asked boyds if I could attach a line to the rollover vent and run it back to my filler neck since it's barbed but they said no. But they also said I shouldn't need a vent line if I had the rollover vent....
So, I guess I will do the return line and vent line and be done with it. I just won't roll the Jimmy and therefore won't need a rollover vent.

Thank you

[C.I.Blazer]

Trying to figure out the same thing installing my Boyd tank. When I spoke to AZPro they said to attache a line to the rollover vent and run it to a high point next to the filler neck and just leave it open. I too want to hook it up to the filler vent and use a vented cap. Can anyone think of a reason why that would not work?

[litebulblsc]

Originally Posted by C.I.Blazer

Trying to figure out the same thing installing my Boyd tank. When I spoke to AZPro they said to attache a line to the rollover vent and run it to a high point next to the filler neck and just leave it open. I too want to hook it up to the filler vent and use a vented cap. Can anyone think of a reason why that would not work?

There is no rollover protection on the fuel filler. The only thing that could stop gas from spilling out would be a sealing cap. If you run a vented cap, and run your vent there, you might as well save your money and nof buy the rollover valve.

The biggest problem with venting to atmosphere, is the ethanol in gasoline is hygroscopic.
It can attract water from the air. Not too big of a deal if it gets driven often, but something that sits can accumulate water in the tank.

[BIG BLOCK JIMMY]

That makes sense on the rollover vent.
Next amateur question: Why are there what appears to be four vent lines as shown in the third pic of this post? Three were connected to the old tank and one was plugged.

[Thealien]

Originally Posted by BIG BLOCK JIMMY

That makes sense on the rollover vent.
Next amateur question: Why are there what appears to be four vent lines as shown in the third pic of this post? Three were connected to the old tank and one was plugged.

READ THIS THREAD HERE IT HAS A DIAGRAM

[C.I.Blazer]

Originally Posted by litebulblsc

There is no rollover protection on the fuel filler. The only thing that could stop gas from spilling out would be a sealing cap. If you run a vented cap, and run your vent there, you might as well save your money and nof buy the rollover valve.

The biggest problem with venting to atmosphere, is the ethanol in gasoline is hygroscopic.
It can attract water from the air. Not too big of a deal if it gets driven often, but something that sits can accumulate water in the tank.

Duh, that makes total sense. I guess I need to find a way to plug the vapor line on the filler neck otherwise fuel would just pour out of it in the event of a roll over. I see that the Boyd tanks now come with a connection on the tank for the vapor return line.

[BIG BLOCK JIMMY]

Originally Posted by Thealien

READ THIS THREAD HERE IT HAS A DIAGRAM

Thank you Thealien for that thread link. That has some great info and certainly answers the question!

[Thealien]

Originally Posted by BIG BLOCK JIMMY

Thank you Thealien for that thread link. That has some great info and certainly answers the question!

When I did my Jimmy 12-13 years ago there was not a lot of this information out there. Myself and a couple of others pushed for the LSX forum here. Many people here helped me a lot with that swap and I wanted to help others if I could. It is a shame so may answers are in that thread and nobody reads it? And photobucket screwed up a lot of the pictures

I am glad you found it helpful. I have been going back to it myself recently.

Too bad my project is FUBAR! The supposed mint 2 wheel drive blazer I bought and just had delivered is a POS!! I am physically unable to do the work due to my shoulder injuries and now a possible $10,000 paint job is going to probably be in excess of $20,000. I was so looking forward to top off cruising this summer. Now it may never happen

Sorry about the rant, pretty bummed out!

[BIG BLOCK JIMMY]

Yes Sir! Without the help of everyone on here, it would have taken me years to get where I am trying to get the jimmy to a condition that I want. I don't mean to digress from this thread, but maybe it will make you feel better. I'll keep it as short as possible to: I bought my Jimmy from a classic car dealer, sight unseen other than pics and video. Paid WAY too much and then had it shipped 1200 miles. Within the first 2 min drive with my wife, I knew the transmission was shot!...this is already getting to be too long of a story. Here are the numbers:
Paid $27,000, another $2,000 for shipping. Two years later I have spent another $20,000 in parts, axle straightening, and some bodywork. I still have a garage full of new stuff to install and after two years we have about a total of 30 minutes of joy riding time. I knew better than to buy something sight unseen as well, so I blame myself. All that being said, I still LOVE IT!