My project 1976 914 was apart when I bought it...including the fuel tank.

How can I tell which fuel line going into the body is the pressure line and which is the return line?

(I've figured out the two on the tank)

Thanks!

-Dick-

if you have the SS lines from Chris, one of them is larger. The larger line is the pressure line to the engine, the smaller is the return.

Zach

If you think about it, it really doesn't matter. One feeds fuel, the other returns. The lines don't care. The one you attach to the feed from the tank just needs to go to the passenger fuel rail, then to drivers fuel rail, then to the pressure regulator, then to the return line

Incorrect.
Try again.

Huh. I have mine plumbed backwards then.

Zach

I believe on a 1976 the feed and return lines are the same size which is 8mm.

Thats so weird. On the Tangerine Racing website it even references for the turbo subie conversions "12.7 mm supply line with 9.5 mm return lines. I would guess that the principal is the same for Porsche EFI. Bigger supply. Smaller return.

this

Thanks. I don't have the SS lines from Chris. My stock lines are the same size. I figured it probably doesn't matter which I use for each function, but I wanted to check since this is my first 914 and I didn't know if there were some unknown factors that might be important.

I do appreciate the help!

My feed line is larger too! Got lines from Tangerine Racing.

Normal convention is supply is to the right of return. On the firewall, the return goes above the supply line.

You might want to consider the SS lines, instead of pressurizing your 40 year old plastic lines. When the pressurized plastic lines fail they don't don't just dribble or seep, they split open.

My have been switched to SS lines through the tunnel and I am running the pump in the rear so neither one will be under pressure.

Jim

Thanks, Chris.

-Dick-

How does your fuel get returned back to the tank if it is not under pressure?

[/quote]

You might want to consider the SS lines, instead of pressurizing your 40 year old plastic lines. When the pressurized plastic lines fail they don't don't just dribble or seep, they split open.

My have been switched to SS lines through the tunnel and I am running the pump in the rear so neither one will be under pressure.

Jim
[/quote]

There's enough pressure to move the fuel into the tank but its not pressurized like the supply side of the fuel circuit before the regulator.

The supply side has the screened sock. It's the line that resides in the small round baffle cup. The other side is the return.

The later cars (75-76 at least) have the same size lines. Both are 8mm, or 5/16 if you want to save some money on the rubber sections. Definitely do the SS in the tunnel. Cheap insurance.

I have to agree on that. '75 I am rebuilding has the same size lines. Get the SS lines that way you do not have to worry about tinkering in the tunnel area.

I was just working getting this figured out last night for listing on our new website.
We have the fuel filter and the lines that go under the tank. Bdstone and I came up with The line that comes from the tank to the filter is larger, then the line to from the filter to the pump and from the pump to the tunnel lines. If you need the rubber and the filter you can get them at http://shop.914rubber.com/Fuel-filter-and-...m?categoryId=-1.