Fuel Line Blockage - New Cleaning method

[zKars]

One of the issues I constantly deal with during a restoration is a gummed up fuel system. Not unusual that it ends up with new hard lines and/or a new fuel tank when things are just too far gone.

I  try to restore the existing lines and tank when ever possible, but it can be a time consuming and often fruitless endeavor in the end.

Yesterday I came up with a new method that allowed me to save both a tank and the main fuel line from replacement.

Sometimes it’s rust in the tank, sometimes it’s old fuel that has turned to solid or semi solid black tar or even hard crystals mixed with that tar. In yesterdays case, it was semi solid black tar. 

I have 11292 under the knife right now, it has sat a long time without attention. (20+ years). Tried to blow air back from the fuel filter end to the tank, nothing. Oh oh….  I pulled the drain plug with a big drain pan ready to catch whatever might come gushing out, but there was nothing. Initially. I looked in the hole, and it was covered with something black. WTH. I grabbed a stiff wire and stuck it in there and poked around and shortly I had a very very slow drip of incredibly viscous black goo begin to ooze out. Wonderful. Let that drip for a while, not very exciting. Took the rubber hose off the tank outlet pipe and then blew shop air into the line from the engine bay end. Nothing. Crap. Pushed a hose on the tank outlet pipe and tried to blow air into the tank. Nothing.  Crap crap. Hard line plugged, tank outlet line plugged. Tank  filled to some extent with something just like Northern Alberta Heavy Crude. My old nemesis is back to haunt me….

 

[zKars]

So my usual approach with fuel line blockage is Lacquer Thinner. That stuff eats fuel deposits like nothing I’ve seen. With a blocked line, you hang up a funnel with a hose into the hard line in the engine bay, fill it with lacquer thinner and wait. And wait, and wait. Eventually the stuff will eat through the goo and clear the line. Eventually

24 hours later and the level of thinner in the funnel hasn’t moved much….. oh oh…..

I start thinking of alternative methods. And start the process to remove the tank. Easier to the thinner wash and line clearing with it out. 

My mind wanders to ways to stick something mechanical into the line to drill it out. Try a hunk of stiff wire, but only goes a bout 2 inched and then the line does a 90. Nope.  Think Roto Rooter with the snake. Nah, ain’t nothing that small around.  Is there?    Hmmmmmm

[zKars]

Last week I was parting out a rotten old ZX and one of the things I pulled out and tossed was the speedo cable. Got one of those in stock already and they don’t work on S30’s. 

Then I start thinking about the rotating core wire. You don’t suppose……..   I go grab it, and have a look. Its pretty long, like about 7 feet long, and has a diameter of about 1/8” or so. real flexible, but the end has stiff part about 1” long that ground down square, like they welded that section to lock the spiral outer core to the center so it would grind down without fraying. It’s too long to make any decent turn in the fuel pipe. Dang it. But if I cut it down to about 1/4” of hard square end it might!

Chopped it off, and I chuck the other end of the thing in a drill, and start stuffing the chopped off end down my fuel line. 

Well I’ll be horn swaggled! That thing digs in and heads on down the line making all the bends along the way. 

[zKars]

Now the pretty pictures cause you’re getting bored of my lengthy explanations…..

Now I have to explain something. While I could drill the line, it didn’t clear it. I had to then move to stage two, which was to hook up my lacquer thinner soak funnel and line, then drill down through that, which got the thinner down into and distributed through the fuel line. 

Edited November 8, 2021 by zKars

[zKars]

After about 15 minutes of drilling, and pushing it in and pulling it out, I saw some magic at the other end of the line. A slow and steady drip of goo coming out of the other end!

 

[Captain Obvious]

That's very cool. Great thinking and adapting!!!     

[zKars]

Pretty soon a stream of lacquer thinner started to flow. I ran a litre or so of the stuff through a couple of times and called it good.

Clearing the tank line was the same deal. I put a section of hose on the tank outlet, about 12 inches, just so that it would curve back out toward the wheel well so it was easier to feed the line in, and just drilled without the funnel and filler for a bit since that is just a short section of hard line in the tank.

That too work lickety split and the line was freed up. Air pressure blew out the rest of what was left.  Yahoo!

Now the goo in the tank was taken care of by 2 gallons of lacquer thinner poured in and sloshed around for a couple of hours and drained out, then put back in, drained out, repeat a few times.

[zKars]

The fuel pump and carbs were simply dry. No Goo. Just needed to cleaned and lubed and set up again. Hope to hear VROOOM today.

Next challange might be the coolant system.

Found this. Might now be a good sign…..

Having spare parts like a speedo cable I could adapt is the key to this, but if you don’t have one, any speedo cable from a junk yard car could work just the same. 

Edited November 8, 2021 by zKars

[Muzez]

1 hour ago, zKars said:

So my usual approach with fuel line blockage is Lacquer Thinner. That stuff eats fuel deposits like nothing I’ve seen. With a blocked line, you hang up a funnel with a hose into the hard line in the engine bay, fill it with lacquer thinner and wait. And wait, and wait. Eventually the stuff will eat through the goo and clear the line. Eventually

@zKars when you clean the lines this way, how do you clean out the Lacquer thinner once you are done? 

[zKars]

13 minutes ago, Muzez said:

@zKars when you clean the lines this way, how do you clean out the Lacquer thinner once you are done? 

Just let it run out. It is highly evaporative and won’t stick around long. Blow compressed air through to get it all I suppose. I’m hoping whatever is left in the gas tank will add a little octane boost!

 

Edited November 8, 2021 by zKars

[zKars]

No one has asked how I shook the tank when it was full of thinner. Tank is in the car, right? 

Take rear wheels off, stash under car. Place floor jack under diff. Jack the back end way up, let the back end down as far as I dare. Jack the back end up, let the back end down. Etc etc etc. Got a great arm workout! 

If you jiggle the jack handle side to side, the whole car wiggles a little too. Front end was on jack stands too. 

[Muzez]

2 minutes ago, zKars said:

If you jiggle the jack handle side to side, the whole car wiggles a little too. Front end was on jack stands too. 

This part would make me a little nervous haha. 

This is another creative approach: