Dirty Fuel Tank

[Meangene83]

1973 plymouth roadrunner, 400 cid, 727 auto, edelbrock 4 brl carb.
So I have a fuel tank that is full of crud. Upon filling up the tank and peering in the filler neck, I could see all kinds of crap floating around in the tank.
This explained why the car had been idling rough and giving me fuel related problems.
The tank was "new" and installed by Previous Owner. Problem is PO was a hack, and most likely did not replace the Sender, sock etc...

So I have on the way (classic industries), a new tank, sender unit, sending unit filter sock, new locking ring and seal and a new fuel pump.


Here is the problem...

I am trying not to replace the fuel lines. What can I expect in the way of crud being in the fuel lines and how should I go about cleaning them?


It was recommended to me to , get some carb cleaner and spray it into the fuel line, then blow compressed air thru the line, while at the other end of the fuel line there is a bucket with some rags to catch any crud. They said to keep repeating this till the bucket at the other end comes out clean.
Sounds like a good plan but I was hoping to hear any other tricks and other TIPS relating to a major fuel system changeover.

A side note, the fuel vapor separtor manifold above the fuel tank? What should I do with this?

Thank you for sharing any wisdom. I will probably tackle this in the coming week.

Gene

==============
HERE IS MY CLASSIC INDUSTRIES ORDER.

K404	FUEL SNDNG UNT FLTR STL 5/16"		UPS	1	$11.99 ea	$11.99
MF292	62-76 FUEL LOCK RING & GASKET		UPS	1	$7.99 ea	$7.99
MF438	71-73 B-BODY SNDG UNT-3/8"		UPS	1	$69.99 ea	$69.99
M6935	73-74 MOPAR V8 400BB FUEL PUMP		UPS	1	$25.99 ea	$25.99
FT6014B	72-73 MPR B-BDY FUEL TANK-NTRN		Oversize-2	1	$199.99 ea	$199.99

 

[HawkRod]

I think your carb cleaner method should work fine. I'd suggest to blow the line out backwards from the front of the car back to more easily dislodge any crap that got in there...

 

[slepr1]

Have you checked the old sender if the sock is still attached? Where is this 'crud' coming from? If its floating its not being sucked up the fuel pick up. I'd cut open the fuel filter (after letting it dry for a day or so) and check what's in it. I did this and found allot of rust scale. I just replaced my tank & sending unit because of this.

I don't see a grommet for the filler hose or straps in your list. Straps can be cleaned up but the grommet should be replaced. Getting the old grommet out intact could be a problem...for $20 a newer style grommet is a great deal. Clean up the filler neck and bracket too. The strap bolts and clips are notorious for being seized or hard to remove. The clips will break if not careful but are replaceable.

"A side note, the fuel vapor separtor manifold above the fuel tank? What should I do with this?" Can't you leave it and rehook it up to the new tank?

 

[Meangene83]

Thank you both, Ordering a new filler grommet!

My feeling is the tank was replaced by PO, and he did not replace the Sender. Simultaneously as the idling problems occured the gauge is reading unreliable measurements.

I am worried I may have sucked up gunk when I ran the tank completely dry. The gauge told me I had half a tank and I ended up running out of gas on the highway. After that I filled up and I noticed the grud floating in the tank. Some of it was green, don't ask me how or why! Also looked like bits of brown rust.

I also should mentioned I had a clear carb filter, inside of that was sand, dirt and small rust chunks.

has anyone ever added any additional fuel filters? At the tank perhaps?
The tiny little carb filter hardly seems sufficient... I would feel more protected with a second filter somewhere in line. Now that I am dumping in $500-600.

- - - Updated - - -

Also, Do you think there is any need to carb clean the Vapor Return line that runs from the Canister back to the Tank?
(I figure I might as well...)

 

[slepr1]

IMO I don't think its necessary to flush anything out. A good filter will catch anything going through it. I've heard of some guys having a coarser mesh filter installed by the fuel tank and the regular fine mesh filter after the pump.

You mention a tiny clear carb filter. I've only seen these ones on mopars and are installed between the pump and the carb.

"The tiny little carb filter hardly seems sufficient" could be part of the problem. I'd replace that first. After the new tank and all is installed, drive a tank or two of fuel and cut open to see if it caught anything. I bet it will be clean as a whistle. If dirt already got through, your carb may need some servicing.

 

[HawkRod]

I think it depends on the condition of your tank. My original tank from my 1970 Road Runner had this fine silt like stuff in it. I tried flushing it out and diluting it out. I then put two filters on the car, both before AND after the fuel pump.

My car had issues and finally stalled in traffic. I found crud in the carb even with the twin filters. That is when I said "enough!" and bought a new tank. No issues since...

 

[Meangene83]

I have a strong feeling crud made it past my filter and into the carb... What am I looking at to get the Carb cleaned and fixed up?
Is this something a a smart novice such as myself can tackle?
It is an edelbrock carb. (not sure of exact model)

It used to be BRAND SPANKIN NEW prior to this rust and crud showing up... So frustrating, only been on it a month.

 

[ckessel]

If the tank is still out, drop some magnets inside of it to capture any future rust that gets it. The trans pan magnets out of the front wheel drive stuff are pretty strong if you have access to them plus there is a hole in the center that you can put over the end of a steel fuel filter to grab stuff before it gets to the carb. Rust will blow by any filter made and plug stuff up.