Fuel line recommendation

[BRGT350]

I am finally getting around to fixing/replacing/updating the fuel system on my 1984 Mustang. That has always been an area that I would update some day, but now to the point where the day needs to be this winter. The original factory lines need to be replaced as they were never designed for a dual exhaust V8, as my car was a 2.3L car from the factory. The metal lines run along the passenger side muffler, and terminate in the engine compartment in close proximity to the header collector on the driver's side. Not good at all. My car also has MM subframe connectors and torque arm, so lots of bits that make running factory lines difficult. I need a fuel line that can go from the fuel tank to the mechanical fuel pump located on the side of the engine block. I have charted out a route that takes the line across the front edge of the tank, over the driver's side axle, down the frame rail, and to the fuel pump with the least amount of bends and the furthest away from moving parts and heat sources.

Now the hard part, what to use?

• Factory bent replacement lines? Probably not due to the proximity to heat sources and difficulty in routing around aftermarket parts.
• Soft rubber, such as Earl's Vapor Guard? This looks like a decent option as it has low permeability and suitable for pump gas, which eats rubber hoses after a few seasons. Bad part is concerns over running soft hose under the car. I would need some road debris shielding.
• Push-Lock hose? Difficult to assemble the barbs on the hose, still a soft hose that is exposed to potential road debris, and some versions are not good for pump gas with ethanol and others leech gas odors/fumes.
• Braided nylon? Ok, better in terms of running under the car, but depending on the type, may only be good for 3-5 years before it needs to be replaced.
• Stainless steel braided? The classic AN style hose, but not suitable for pump gas unless it has a PTFE liner, meaning it needs special fittings to assemble. Permeation of fumes is also a concern. Cost to run decent stainless steel line from the tank to pump can cost well into the hundreds and still may not last long. Also stainless steel has electrostatic concerns as electricity can arc between the fuel and stainless steel, causing pinholes in the PTFE lining, which leads to leaks.
• Modern nylon fuel line? This is what OEM's use today and is impact resistant for under car use. It can be formulated with ETFE to resist electrostatic buildup and protect the nylon from being attacked by the pump gas. Bad thing is trying to find OEM spec nylon fuel line. Not like Ford will just sell a 20 foot roll of it. Aftermarket stuff is questionable for what the composition of the nylon is, so getting it wrong could be very bad.
• Stainless steel hard line? Tough to route, tough to bend, need to be flared to work, but suitable for under the car.

So, lots of options, none are good. I have posted over on Corral, but not happy with the results. Most are running EFI and solutions suggested are of questionable quality and safety. To make things worse, every option I research has one article saying to avoid it while the next article says it is the best solution. There must be something that can connect the tank to the pump, work with pump gas, won't crumble in a few years, and doesn't cost more than the car. I am not running the 24 hours of LeMans with the car.

[K_Mac]

I'll most likely be running the black coated stainless braided PTFE lined fuel line on my car. Downside is cost as you mentioned. Low permeation and the black coating should cover the possible electrical arc concern you mentioned.

[Broncojunkie]

What about nickel copper lines? You could use short section of fuel hose wherever there is an inline filter or where it meets the pump and carb. The fuel hose could be regular rubber hose or you could put AN fittings on it, etc.

[Sask84gt]

I used hot rod fuel hose on my 84. Ran from Tank to holley black pump right into engine bay. Great company to deal with. Awesome line and fittings. Tons of colors to choose from.
https://hotrodfuelhose.com/?gclid=Cj...RoC2MoQAvD_BwE

[BRGT350]

I'll most likely be running the black coated stainless braided PTFE lined fuel line on my car. Downside is cost as you mentioned. Low permeation and the black coating should cover the possible electrical arc concern you mentioned.

I just heard back from Summit for their suggestion based upon my application and they said the black braided Vibrant -6AN PTFE line. Looking at cost, it isn't much more (~$60) than high quality ethanol resistant soft rubber fuel hose. That might be the best option.

[BRGT350]

What about nickel copper lines? You could use short section of fuel hose wherever there is an inline filter or where it meets the pump and carb. The fuel hose could be regular rubber hose or you could put AN fittings on it, etc.

I haven't looked at nickel copper, but will do so. I would run a hard line along the frame rail and use soft hose to the pump and from the tank, similar to what the factory used.

[BRGT350]

I used hot rod fuel hose on my 84. Ran from Tank to holley black pump right into engine bay. Great company to deal with. Awesome line and fittings. Tons of colors to choose from.
https://hotrodfuelhose.com/?gclid=Cj...RoC2MoQAvD_BwE

Now that Summit gave the thumbs up to the PTFE black braided hose, I will look more at the Hot Rod products. I had looked over their website, but wasn't even sure where to start in order to know what to look at. I can totally see using the Hot Rod stuff in the engine compartment where you can see the lines and fittings and isn't in the path of road debris.

[Sask84gt]

Now that Summit gave the thumbs up to the PTFE black braided hose, I will look more at the Hot Rod products. I had looked over their website, but wasn't even sure where to start in order to know what to look at. I can totally see using the Hot Rod stuff in the engine compartment where you can see the lines and fittings and isn't in the path of road debris.

If you go to the contact us in their website and send them a message through facebook Justin will get back to you and answer all your questions. Pretty sure he is the owner and operator. I just told him what I wanted to do and he hooked me up with everything i needed.

[BRGT350]

If you go to the contact us in their website and send them a message through facebook Justin will get back to you and answer all your questions. Pretty sure he is the owner and operator. I just told him what I wanted to do and he hooked me up with everything i needed.

Awesome! I will do that for the engine compartment hoses. Settled on Vibrant PTFE for under the car, which is the most critical to replace this winter. The engine compartment hoses are new ethanol resistant rubber, so I can hold off on those until next winter. I do like how that Hot Rod stuff looks.

[Sask84gt]

Awesome! I will do that for the engine compartment hoses. Settled on Vibrant PTFE for under the car, which is the most critical to replace this winter. The engine compartment hoses are new ethanol resistant rubber, so I can hold off on those until next winter. I do like how that Hot Rod stuff looks.

Awesome, good luck!

[massacre]

Hot rod fuel hose here too. Great company to deal with.

[gr79]

Whatever material used, do consider routing more to center of car when possible under the floor pan.
More chance of damage if running down rocker area.
Jacks, post hoist pads, debris kicked up by front tires.
Rubber is traditionally used for 12" runs or less. Metal is tougher than nylon. Support the run well.

[Jack Hidley]

Why don't you use SS lines designed as replacements for a 1985 Mustang with dual exhaust? These will fit all of the parts installed on your car, not rust and won't get torn open if the car drives over something on the road. For the ends of the tube, you can use black Teflon hose to connect it.

[BRGT350]

Whatever material used, do consider routing more to center of car when possible under the floor pan.
More chance of damage if running down rocker area.
Jacks, post hoist pads, debris kicked up by front tires.
Rubber is traditionally used for 12" runs or less. Metal is tougher than nylon. Support the run well.

Looking to run along the frame rail, but on the pinch weld side so I can get further away from the exhaust. Agree that the rocker/pinch weld area is too prone to impact damage. I need to build an inner fender splash shield this winter (my car hasn't had inner fenders for almost 15 years now) and might build a shield over the fuel line under the floor pan from the wheel well to torque-arm/sub-frame connector connection. I use impact resistant plastic as underbody shields on my Fiesta ST for the winter and that stuff holds up remarkably well.

[BRGT350]

Why don't you use SS lines designed as replacements for a 1985 Mustang with dual exhaust? These will fit all of the parts installed on your car, not rust and won't get torn open if the car drives over something on the road. For the ends of the tube, you can use black Teflon hose to connect it.

That was one of my original plans. Oddly, trying to find the routing of the 85 GT fuel lines has been tough to track down. I have the 85 shop manuals, but the fuel line diagram is really tough to figure out the routing. Until a few years ago, I had access to a pristine 85 GT that I could have used to track the fuel line routing. My dad moved his 85 GT down the Florida, so it is 1200 miles away. The biggest reason that I decided against the 85 GT factory lines is trying to route them on an assembled car. Getting the pre-bent lines around the sub-frame connectors, over the driveshaft, and from the tank to pump isn't easy. Trying to get the old lines off the car with everything installed is proving to be a challenge. I have already cut the factory lines to remove it and even in sections, it is proving tough to get out. In hindsight, I wish I would have installed the lines when the car was a lift and stripped down before the sub-frame connectors, driveline, and suspension installed. Now the car is assembled and I lost access to a nice lift that made every project so much easier.

[massacre]

I ran my fuel lines on the sides of the tunnel. I do have a driveshaft loop tho.

[BRGT350]

I ran my fuel lines on the sides of the tunnel. I do have a driveshaft loop tho.

I would have to cross-over the exhaust if I ran down the tunnel. I have more room back by the panhard rod and front of the tank to make the crossover to the driver's side and then run forward to the driver's side wheel well. I plan to run the line in front of the tank, near the panhard rod structure mounted to the frame, turn forward at the rear frame rail by the axle bump stop, follow the frame rail to the torque box, forward at the frame rail, go around the floor braces for the subframe connectors, back to the frame rail, into the wheel well along the frame rail, forward along the k-member, and then make a final turn to the fuel pump. Use rubber lined clamps every 12-18" to secure the line to the chassis. That is the straightest route with the least number of connections and furthest away from any heat sources or moving bits.

[Jack Hidley]

I can post photos of where they run on a 1985 with dual exhaust, if you are interested.

[BRGT350]

I can post photos of where they run on a 1985 with dual exhaust, if you are interested.

Yes, that would be great!

[Jack Hidley]

The fuel lines in the front go where they basically go on all Fox Mustangs. They travel across the floor pan where the lateral divot is in it, to get to the outboard side of the frame rail. They then run up the side of the frame rail, bend upwards into the slight notch in the A-pillar brace, then up the right side of the frame rail. I do not know if they go to the front of the k-member, then under it to get to the engine or go into the hole in the inner fender near the firewall.

[BRGT350]

Thanks Jack, so the fuel line is the pair going down the driveshaft tunnel? I recall the 85 GT has a return line.

What is the line that sits on the inside of the rear frame rail and angles up towards the rear upper spring seat? It is the one just above the oval to access the LCA. That is the fuel line on my 84 Mustang. With dual exhaust, it is right up against the muffler. The line went forward to about where the torque arm nose sits and then crosses over the transmission tunnel, and turns towards the front near the driver's side pinch weld. At the wheel well, it turns right, then up into the wheel well, goes between the k-member and frame, and terminates laterally where the header collector sits. That spot is also bad news for a V8 as it is almost impossible to attach to the metal line without running super close to the header collector.

[wraithracing]

The line is question on the inside of the rear frame rail is an emissions/charcoal cannister line from the fuel tank.

[Jack Hidley]

Yes.

I don't know what that third line is. I assume that it is a vent line to go to the charcoal canister. Remember, 1985 is a very weird year for the car. There are two V8 engine options (CFI and 4 barrel carb), that use different exhaust systems and totally different fuel line and brake line routings as one engine has dual exhaust and the other does not. Some of the lines might be the same between the two engine applications in this year. The CFI application has the fuel pump mounted right where the right hand muffler goes, so maybe that isn't possible after all.

[BRGT350]

My 84 had the vapor canister and lines, but no idea where those used to run. I think that system came out back in 1996 when I put the 302 in it while I was in high school. I recall the canister was up front on the right, near the passenger wheel well and radiator.

Yeah, 85 was a weird year for sure. I know that on my dad's 85 GT, whenever something needs to be fixed, there is always some weird issue in finding the right parts and getting things to work. I recall he had some fuel issues after the car sat for 15+ years and needed work to the fuel tank, lines, carb, and pump.

Looking at the 85 shop manual for V8 manual transmission, I would have not guessed the fuel lines ran down the center of the driveshaft tunnel. The diagram is of a partial frame and difficult to get a good frame of reference. I will go back and look at it tonight and see if I can make more sense of it. Also look for the evap line that is the fuel supply line on my car, or what used to be the supply line since it is now coming out.

Once I get my car back together, the plan this spring is to burn as much fuel as possible and then replace the tank. The rubber line on the top of the fuel tank has swollen to bigger OD than 3/8" hose. It is amazing that line has survived this long. I bet the inside of the tank is sketchy at best. My dad has already gone through 2 new fuel tanks on his 85 GT. His 89 SSC still has all the original lines and tank. He is now running ethanol free gas in both of his Foxes and SN95. He had factory rubber lines come apart on his 94 GT and the fuel management unit for the supercharger had the internal diaphragm disintegrate. None of these cars have many miles on them, probably less than 20,000.

[BRGT350]

Finally got all the old lines out of the car. Needed to cut the metal line in a few places to get it out as it was always stuck on something under the car. Based upon the pictures of the 85 GT and comments here, I think I am going to try around route the -6AN line from the center of the fuel tank forward along the driver's side of the driveshaft tunnel, and then turn to go between the floor and sub-frame connector. This assumes the -6AN hose end will fit between the floor and subframe connector. The routing would be fairly close to the factory 85 GT and that should be the furthest away from any heat sources as well.