Plugged return fuel line

[JSM]

Any suggestions on how to unplug?  Searched and some folks said compressed air, tired that from either end disconnected from the tank and the rail, nada.  Someone else mentioned small wire.  Where you getting piano wire from, hobby store?

[SteveJ]

10 AWG solid wire: https://www.amazon.com/Ground-Wire-Copper-Listed-SATELLITE/dp/B00JJTPWII

You can also get 8 AWG bare solid wire from Home Depot or Lowes for 59 cents/foot. That's a little over 1/8 inch in diameter. It should fit inside the return line easily.

[Dave WM]

I have some pretty stiff wire used for tying rebar. I tried it on the evap line but it was too tight could not make the bends. the fuel line is bigger might work there, come and get it, I got a huge roll.

[JSM]

i tried two different small gauges of piano wire.  It's only a 3/16 line so... First was a no go.  Went back and got the smallest flexible i could but still stiff.  It is tiny. I was able to make the first bend in the engine compartment and only went about 5".  I'll try from the tank side tomorrow to ensure it's a clog and not the wire.

Has anyone ever cut the fuel line before and used a brake tool flare to remake the end barb?

[Dave WM]

did you try lube on the wire, may help.

[zKars]

IF the plug is fuel varnish, then pore laquer thinner in the tube and be patient. It will dissolve the plug. May take a few attempts dependng on the extent of the plug, but it will get it clear. 

[grannyknot]

Do you have a line trimmer, string trimmer, weed wacker in the garage?

[gwri8]

1 hour ago, JSM said:

i tried two different small gauges of piano wire.  It's only a 3/16 line so... First was a no go.  Went back and got the smallest flexible i could but still stiff.  It is tiny. I was able to make the first bend in the engine compartment and only went about 5".  I'll try from the tank side tomorrow to ensure it's a clog and not the wire.

Has anyone ever cut the fuel line before and used a brake tool flare to remake the end barb?

A while back I had clogged lines inside a fuel tank I refurbished.  At first I tried wires with no success and wound up cutting and then clearing them with paint thinner like zKars just mentioned.  The thinner works really well.  As for the cut lines, I suppose you could use a flaring tool to rejoin, That was my first thought but I found that compression joints were quicker. For that length of tubing, would it just be easier to replace the whole line?

[JSM]

1 hour ago, grannyknot said:

Do you have a line trimmer, string trimmer, weed wacker in the garage?

Good thought. I have tons. 

[JSM]

1 hour ago, Dave WM said:

did you try lube on the wire, may help.

That's what she said!  

1 hour ago, zKars said:

IF the plug is fuel varnish, then pore laquer thinner in the tube and be patient. It will dissolve the plug. May take a few attempts dependng on the extent of the plug, but it will get it clear. 

My return fuel pressure was a nice stream when i took of the fuel line in the engine bay. I know it's not the same as lacquer thinner but I figured it's been sitting with fuel for awhile. 

9 minutes ago, gwri8 said:

 For that length of tubing, would it just be easier to replace the whole line?

It runs the full length of the car. I think worse cast scenario I can run a rubber fuel line from front to back and not use it for the time being. I have a feeling the tank is coming out soon anyway and I'll want to upgrade to FI I'll need a bigger return anyway. 

[Zed Head]

Does anything pass through at all?  You might use a high pressure EFI pump or even just a low pressure pump and set up a loop, with a small tank of carb cleaner or similar.  An EFI pump will have pressure and volume.  Let it run and purge it.  Run it backward also.

[JSM]

19 minutes ago, Zed Head said:

Does anything pass through at all?  You might use a high pressure EFI pump or even just a low pressure pump and set up a loop, with a small tank of carb cleaner or similar.  An EFI pump will have pressure and volume.  Let it run and purge it.  Run it backward also.

Nothing. I'm running 125 psi air pressure holding as tight as I can. Nada. 

2 hours ago, grannyknot said:

Do you have a line trimmer, string trimmer, weed wacker in the garage?

This was brilliant and has worked best so far. From the front I can get about 3' and it stops.  Puts me to edge of battery. The concerning part is from the back. I can get 6' in. Lots of lube and the back should go in the furthest. I think I'm ending up right about mid tranny.  I've tried and tried with same results.

If I can't get to much further from the front I'm going to cut it at the firewall and flare it there. Then try from the front again. More tomorrow. Wife gave me the look of death for going in the garage. 

Geese at least I got out of my good clothes. 

Edited July 15, 2017 by JSM