Going EFI-Need advice on fuel hose selection

[4mm]

Hello all,

I'm going the EFI route and one subject I have little knowledge in is fuel hose selection. I've had stainless braided I the past and I didn't like the fact that fuel smell would somehow seep through and that eventually you have to replace the hose earlier than other types.

I've been looking into push lock PTFE rubber hose as my choice. Anybody have any feedback on this type of hose or a better recommendation?

 

[barnett468]

regular fuel injection hose.

 

[jbojo]

Need to use good clamps too. System will produce 70psi fuel pressure and you don't want a line coming off. Something like this.

https://www.msdperformance.com/products/fuel_systems/atomic_efi/atomic_tbi/parts/2928

 

[Mesozoic]

Definitely PTFE lined hose. The Summit stuff is cheap and high quality PTFE. If you don't run PTFE you'll eventually have fuel permeation through the hose and an odor to match. I used AN fittings throughout my system.

 

[InjectedMach]

Lined hose 100% or you will regret it.

 

[71XR7VERT]

I replaced the original lines in my car with metal tubing for the long runs from the tank to the engine and back, using fuel injection hose for the connections to the tank and engine from the lines.

Installed pre and post fuel pump filters as well .

 

[4mm]

I replaced the original lines in my car with metal tubing for the long runs from the tank to the engine and back, using fuel injection hose for the connections to the tank and engine from the lines.

Installed pre and post fuel pump filters as well .

That's what I was originally going to do to preserve the OEM look and it's metal tubing that I believe will last longer.

The instructions clearly state not to use stainless tubing? I don't know why though.

 

[jbojo]

I replaced the original lines in my car with metal tubing for the long runs from the tank to the engine and back, using fuel injection hose for the connections to the tank and engine from the lines.

Installed pre and post fuel pump filters as well .

That's what I was originally going to do to preserve the OEM look and it's metal tubing that I believe will last longer.

The instructions clearly state not to use stainless tubing? I don't know why though.

If you use hard lines and don't use a return system with a regulator you will see a hammering effect on hard lines when the pumps cycles. My system recommended the soft efi lines. Most pumps operate in PWM mode (Pulse Width Modulated) to reduce the loud pump noise with these systems. The PWM mode cycles the pump on/off to maintain fuel pressure so these surges affect the system operation with hard lines while the soft lines absorbs some of the surges.

You can use the vapor return lines in our cars for the fuel return from a regulator and then the use of the hard line would be acceptable. In my case I used soft lines from the tank, a fuel regulator and the the vapor return line with no issues so far.

 

[Mesozoic]

I'm not sure I would use the fuel vapor line as the return, tempting as it may be. I don't think it's got the diameter you ideally want for a return system.

I replaced the original lines in my car with metal tubing for the long runs from the tank to the engine and back, using fuel injection hose for the connections to the tank and engine from the lines.

Installed pre and post fuel pump filters as well .

That's what I was originally going to do to preserve the OEM look and it's metal tubing that I believe will last longer.

The instructions clearly state not to use stainless tubing? I don't know why though.

If you use hard lines and don't use a return system with a regulator you will see a hammering effect on hard lines when the pumps cycles. My system recommended the soft efi lines. Most pumps operate in PWM mode (Pulse Width Modulated) to reduce the loud pump noise with these systems. The PWM mode cycles the pump on/off to maintain fuel pressure so these surges affect the system operation with hard lines while the soft lines absorbs some of the surges.

You can use the vapor return lines in our cars for the fuel return from a regulator and then the use of the hard line would be acceptable. In my case I used soft lines from the tank, a fuel regulator and the the vapor return line with no issues so far.

 

[4mm]

Isn't the vapor return 3/8ths? Is that sufficient for 425hp?

 

[Mesozoic]

Isn't the vapor return 3/8ths? Is that sufficient for 425hp?

My vapor return is definitely not 3/8 tubing. My car is a '71 however, so perhaps the later years with additional emissions equipment had larger lines?

 

[jbojo]

Isn't the vapor return 3/8ths? Is that sufficient for 425hp?

I actually used a drill and enlarged the opening in the cap to create more volume. No issues so far with the return. My motor should be putting out at least 425 HP. The supply line is 3/8th inch if I remember correctly.

 

[Mesozoic]

Yeah, my primary feed line is -6AN along with the return. The vapor line looks like it's -4 or smaller. I'm running my vapor line to a late model Crown Vic canister controlled by the EEC-V purge solenoid.

 

[vozaday]

If you haven't already purchased the system maybe check out FiTech's enclosed sump pump system. Removes the need to run a recirc line back. It is pricey though.

 

[TommyK]

Isn't the vapor return 3/8ths? Is that sufficient for 425hp?

I actually used a drill and enlarged the opening in the cap to create more volume. No issues so far with the return. My motor should be putting out at least 425 HP. The supply line is 3/8th inch if I remember correctly.

John,

I am contemplating upgrading to an in tank pump and using the existing vapor line as a return. Is there a check valve at the tank on the vapor line? I believe my vapor line is 5/16".

Apologies to OP if this is a hijack in progress.

 

[71XR7VERT]

I replaced the original lines in my car with metal tubing for the long runs from the tank to the engine and back, using fuel injection hose for the connections to the tank and engine from the lines.

Installed pre and post fuel pump filters as well .

That's what I was originally going to do to preserve the OEM look and it's metal tubing that I believe will last longer.

The instructions clearly state not to use stainless tubing? I don't know why though.

I like the metal lined in case anything hits them they are tougher than rubber. Not sure on the stainless, but it's tough to bend.

Isn't the vapor return 3/8ths? Is that sufficient for 425hp?

I actually used a drill and enlarged the opening in the cap to create more volume. No issues so far with the return. My motor should be putting out at least 425 HP. The supply line is 3/8th inch if I remember correctly.

John,

I am contemplating upgrading to an in tank pump and using the existing vapor line as a return. Is there a check valve at the tank on the vapor line? I believe my vapor line is 5/16".

Apologies to OP if this is a hijack in progress.

Mine had no check valve but that vent line did have a very small orfice in the vent piece on top of the tank.

 

[jbojo]

Isn't the vapor return 3/8ths? Is that sufficient for 425hp?

I actually used a drill and enlarged the opening in the cap to create more volume. No issues so far with the return. My motor should be putting out at least 425 HP. The supply line is 3/8th inch if I remember correctly.

John,

I am contemplating upgrading to an in tank pump and using the existing vapor line as a return. Is there a check valve at the tank on the vapor line? I believe my vapor line is 5/16".

Apologies to OP if this is a hijack in progress.

There are no check valves. There is a screen and what I believe was a foam filter behind the screen that was pretty much gone. I removed the screen and foam and then used a drill that was slightly larger than the existing hole and opened up the hole a little. I made sure that there was sufficient metal left so that I could clamp the hose on without crushing the tube. My system maintains consistent pressure at idle and while running so the return line has sufficient volume capacity for my application.

 

[4mm]

If you haven't already purchased the system maybe check out FiTech's enclosed sump pump system. Removes the need to run a recirc line back. It is pricey though.

They have turned out to be faulty. I never considered it because it's just adding another component and another connection that can fail.

You can read this link, the final pages are an interesting read.

http://www.corvetteforum.com/forums/c3-tech-performance/3670852-fitech-go-efi-review-12.html

 

[71XR7VERT]

If you do use the vapor as a return, the tank will still need a way to vent pressure changes in the tank and allow air in to replace the fuel used

I installed another dedicated return fitting in my set up, and ran soft lines to just past the pump and at the return fitting, as well as the vent line for about a foot or so.

Engine has soft fuel lines as well. In between is metal pipe.