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EFI fuel lines

RapidRabbit

RapidRabbit

Well-Known Member
Donator
So I'm told I need to get the June COTM back on the road........ :steer

I need to run new fuel lines for the 5.0 EFI engine.

I need some help. I was going to run 5/16 steel lines for both return and feed lines.

Picked a Ron Morris fuel sending unit and realized the feed line is 3/8.
The fuel pump I bought 2 years ago is 5/16 inlet and outlet.

Is 5/16 too small for a feed line?

Also should I run the fuel filter before or after the pump?

I was thinking I could find an adapter to reduce the outlet to 5/16 hose before the fuel pump and go 5/16 from there to fuel rails?

Any suggestions would be appreciated. Plumbing is not my strong point.
 
5/16" lines were the factory size for a 5.0. If you haven't modified you engine much, it will do fine. I think you'll find several arguments for filter placement. I say, after the pump. Why? It was the location Ford chose! If you go to the Dorman website and download their pdf catalog, you'll find a TON of useful adapters. Dorman products are pretty easy to obtain at pretty much all parts stores.
 
That's what I originally thought.
The engine is pretty stock so I figured if it came with 5/16 that should be fine.

So no issues if I convert from 3/8 to 5/16 before the pump?

I have been wading through the dorman catalog. Haven't found the right adapter yet. I found one that goes from 3/8 soft line to 5/16 hard line, but I need to run soft line to the pump first?

22972410_dag_4920311_pri_detl.jpg


I think I'm making this to complicated. maybe over thinking it.
 
Can to change the fuel pump inlet fitting to 3/8" and leave the outlet at 5/16"? I agree that 5/16" fuel line will be fine.

It is actually best to run a filter before and after the pump. A finer filter after the pump (100 micron). That way you don't get debris in your pump and burn it up. Low pressure soft line is fine from the tank to the fuel pump but high pressure should be used after it.
 
Pat I would say you'll be fine using a rubber (fuel rated), line from the tank to the pump. You may check your pump and see if it has removable fittings on the inlet and outlet. If so, it simplifies things by using a style of fitting you posted to adapt down the size.

I have Ron Morris sending unit also (when I was going to use an external pump). I since discovered I could use the pump set up from the '91 I cannibalized for the drive train. It saved me from worrying about fittings and noise, but I did have to adapt a couple of lines so everything connected. I fell into the trap of over thinking it and about drove myself crazy! After a few scans through the Dorman catalog it worked out with just a couple of adapters. Always keep one thing in mind; the less number of fittings and adapters the better. Less connections equal less chances of leaks. A VERY important thing because you're dealing with pressurized fuel.
 
So my fuel rails look like this.
y5uzetyp.jpg


Is this the connector I need? One of each size.
baraqe6u.jpg
 
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Yes, That will work. there are two different sizes for the feed and return side. Earls makes those same fittings to connect an AN-6 fuel line. They or Russel also have a fitting to attach the -6 line to a 5/16 hard line.

If you use the Ford style with the plastic hose, you can use a regular 5/16" compression fitting to mate the hose to the hardline. Just be sure to insert a brass insert sleeve into the plastic line to support the hose. I used this method for about 3 years before converting over to the AN-6 lines.
 
Ok. That's what I thought. I see both sizes from dorman. I saw the Russell ones with the an fittings too. I really don't know much about running an lines.

What kind of sleeve do you mean?
 
"RapidRabbit" said:
Ok. That's what I thought. I see both sizes from dorman. I saw the Russell ones with the an fittings too. I really don't know much about running an lines.

What kind of sleeve do you mean?
Click to expand...

There are a couple of sample photo's at near the bottom of this web page... http://www.plumbingsupply.com/compress.html
The concept is the same for the EFI fuel line, except I used the brass ferruls not the plastic like shown.

Do you have the hard lines that go from the fuel rail down along the front / side of the engine, or are you planning to run the plastic line right up to the fuel rail? Let me know if you need pics of what I'm talking about.
 
I was planning to run steel line from the pump to the inner fender, then soft line up to the fuel rail.
 
"RapidRabbit" said:
I was planning to run steel line from the pump to the inner fender, then soft line up to the fuel rail.
Click to expand...

Absolutely the way to go. Hard lines would not allow for engine movement and could eventually fail (really, REALLY bad juju!). That's why Ford ran flexible lines from the body mounted lines to the engine connections.
 
Either one will work, but I'd use the second one.

Also on the hard lines, I wasn't referring to running hard lines all the way to the fuel rails...
Your photo above seems to be missing the lines that run to the bottom of the motor. The flexible lines normally tie in at the bottom of the vertical hard lines.
hard_lines.jpg


I swapped the hard lines out for steel braided lines for routing purposes. I know EFI Fuel rated hose is good stuff, but Ford probably ran a hard line on the front of the motor for safety issues. It's kind of a pain to install steel braided lines to AN-fittings, but if you are going to run soft lines directly to the fuel rail, I think I would recommend using the AN fittings and either steel braided line, or perhaps the nylon braided lines. It cost me about $160 run two sections about 3 ft long last year.
braided_lines.jpg


The plastic line is easy to work, but still worry about puncturing it in a collision... To me better to use hardlines or steel braided lines going up to the fuel rail. JMHO...
 
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Thanks for the all the help. :thu

I ordered the second reducer from jegs. That was what I have been looking for for a while. Amazing how using one different word in the search and I found it right away. I kept searching adapters instead of reducers.

Now that I have the back end figured out I will see about the fuel rail connections. Not sure exactly what the plan is there yet.
 
"RapidRabbit" said:
Is this the connector I need? One of each size.
baraqe6u.jpg
Click to expand...

Pat,

Do you need a couple of those efi connectors? I think that I have a set of them that I bought and didn't use. I'm not using stock fuel rails on my setup. Let me know if you'd like me to send them your way.
 
Thanks Rob, but I ordered some from rock auto a few day ago. I needed parts for my infiniti so I just added those in. They were like $4.
 
"68EFIvert" said:
Can to change the fuel pump inlet fitting to 3/8" and leave the outlet at 5/16"? I agree that 5/16" fuel line will be fine.

It is actually best to run a filter before and after the pump. A finer filter after the pump (100 micron). That way you don't get debris in your pump and burn it up. Low pressure soft line is fine from the tank to the fuel pump but high pressure should be used after it.
Click to expand...

I've always read that the pre-pump filter should be 100 micron and the post pump filter 10 micron.
 
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