Main and Return Fuel Lines Help

[supradan]

Hey folks,

I have a 1977 2.7 liter with 40IDA Weber carbs that I'm in the process of replacing an old worn-out fuel pressure regulator with a PMO one. In its current configuration, I only have the main fuel line directly connected to the old FPR. However, with the new FPR I plan to reintroduce the return line into the system by connecting it to PMO FPR.

Here's where the issue is. Both lines are way too short to connect them into the PMO FPR. It seems the previous owner cut them and decided to plug the return line and just connect the FPR into the main line with a small fuel filter. This setup did not require the hoses to be long. However, with the PMO regulator being positioned in the middle of the engine bay (typical location of a PMO FPR) I do not have enough hose to reach the FPR.

Without going to a AN braided setup, what are my options for replacing these hoses with longer ones?

Any help is certainly appreciated.

Daniel

[snbush67]

What pump are you using? It likely isn’t the stock pump, because there would have to be a return line currently.

So if it is a low pressure pump you can get away with clamps and replace in the lines from the tunnel to the engine bay.

But if you have the high pressure pump or are installing a high pressure pump then you should replace with high pressure connections.

[supradan]

Originally Posted by snbush67

What pump are you using? It likely isn’t the stock pump, because there would have to be a return line currently.

So if it is a low pressure pump you can get away with clamps and replace in the lines from the tunnel to the engine bay.

But if you have the high pressure pump or are installing a high pressure pump then you should replace with high pressure connections.

You are correct the fuel pump is not stock. Below is a link the fuel pump model details. It's rated at 5 PSI.

So this now begs the question, do I even need a return line?

https://www.carparts.com/fuel-pump/drivemotive/repv314515

[supradan]

Does anyone know the exact fitting I would need; I believe it's a female M14 barbed, but does it need to be a swivel kind?

Lastly, where can I source these fittings and hoses?

Again, any help is greatly welcomed.

[snbush67]

Are you using/keeping the stock accumulator and filter? If not then go under the car and check the connections where the lines go into the tunnel. See if the hoses have aftermarket clamps on them or if they are factory crimped.

[supradan]

Originally Posted by snbush67

Are you using/keeping the stock accumulator and filter? If not then go under the car and check the connections where the lines go into the tunnel. See if the hoses have aftermarket clamps on them or if they are factory crimped.

I do not have the stock accumulator or filter. Both lines coming from the tunnel to the engine bay seem to be stock as they have stock fittings.

Do you know what size hose and fittings I would need? Did do a search and there is a lot of chatter that makes hard to determine correct information.

[Tremelune]

My 1970 2.2 has Webers, no regulator, and no return line. Whatever the pump in the front is putting out is apparently close enough for the carbs, and gas still goes through at a rate that it's never boiling back there.

Having a return line and regulator is better (particularly in hot traffic), but...doesn't seem wholly necessary.

[snbush67]

Remove the M 14 female fittings from the old fuel lines. Use new 08×13 fuel line. Attach to new fuel lines to the M14 fittings with clamps.

Any local auto parts store should have hoses and clamps.

[BoxsterGT]

I just finished a set of E-85 Hoses for a PMO with AN6 Fittings at the Reg and Carbs....



I can make up new E-85 Rated Hose from the Tunnel to the Filter (if original).....



and Filter OUT Hose (M14 Female 120) to PMO Reg with a Hose nipple.

I can also make up the Return from this Reg to the Tunnel w M14 Female at the Tunnel end.

The Metric fittings will be crimped, the hose nipple ends will have Norma Clamps.

Please email me if this will help.

len.cummings @ verizon.net

[Zuffenwerker]

Boxster GT seems to be your best bet if you want to plumb it that way.

If you don't want a FPR or return line:

Check your fuel pressure, if you are at 4psi you don't need a reg. For Webers I like a hardi or facet pump. They look correct because they came on the carb cars back in the day. Usually the pressure is just right.
With low pressure like that you do not need a return. Certainly fine and well if you want one but when it comes down to it not necessary. The Hardi pump is especially good for cars with no return because it seems to stop pumping once the needle valves are closed.

Daniel

[BoxsterGT]

"it's not leaking....it's just marking it's territory"

Love your post comment Daniel.

Len

[supradan]

Originally Posted by BoxsterGT

I just finished a set of E-85 Hoses for a PMO with AN6 Fittings at the Reg and Carbs....



I can make up new E-85 Rated Hose from the Tunnel to the Filter (if original).....



and Filter OUT Hose (M14 Female 120) to PMO Reg with a Hose nipple.

I can also make up the Return from this Reg to the Tunnel w M14 Female at the Tunnel end.

The Metric fittings will be crimped, the hose nipple ends will have Norma Clamps.

Please email me if this will help.

len.cummings @ verizon.net

Thank you everyone for your input, sincerely appreciated. I’m discussing fuel lines with Len, so hopefully I can get the fuel system done soon here.

Hi Len,

Thank you for your expertise and flexibility. Can’t wait to get these gorgeous hoses in.

Daniel

[Zuffenwerker]

Originally Posted by BoxsterGT

"it's not leaking....it's just marking it's territory"

Love your post comment Daniel.

Len

Len that was my dads theory after 40+ years of owning a Porsche shop. He always kept things light!

Your products look great.'

Daniel