Best way to clean out a fuel tank - 77 280z

[ISPKI]

Hey guys, still trying to find the culprit that is preventing my car from running smoothly. I was going through my list of stuff to check and recalled that when I dropped the fuel tank, it had about 2 gallons of year old gas left in it along with some rust particles and what not. I got to thinking that I may need to properly clean it out. I talked to my buddy about this and he said we may need to cut the tank to gain access to the inside. He was thinking that cutting the tank in half might be the best way to go about this. Has anyone had any experience in cleaning the inside of the tank? Also - Do the tanks in these vehicles have large baffles or chambers to prevent sloshing gasoline, or are they just wide open?

[ISPKI]

Also - I looked into the muriatic acid wash and POR15 sealer method, seems like a good idea.

[Tristin]

To clean mine I drained it and then blew it out with compressed air. Then used acid... Depending on what cane out I would used CLR and either a bunch of nuts and bolts or a small length if chain. Then shook the crap out of it knocking all the stuff off the inside. Thoroughly rinsed with water, then compressed air again, and then I let it dry for the day. Next day cover the inside in POR-15. Good as new!

 

Edit: also, if the gas was sitting in the tank, it was sitting in the lines. If you're not replacing them, make sure you blow them out.

[datzenmike]

When I drove my 710 home (about 90 miles) the filter plugged twice. I put a new one in at home and within a week was plugged again. No way around it... I pulled it out, removed the float, threw two hand fulls of driveway gravel in it, swished it around for 5 min. and rinsed it out with the garden hose. Dumped it out, drained for 1/2 hour and installed with new filter. It also has a functioning return line so unused fuel goes back in the tank. It gets constantly circulated and any rust is caught in the filter keeping the tank clean.That was two years ago and my wife drives it every day in the summer.

[VintageRice]

When I drove my 710 home (about 90 miles) the filter plugged twice. I put a new one in at home and within a week was plugged again. No way around it... I pulled it out, removed the float, threw two hand fulls of driveway gravel in it, swished it around for 5 min. and rinsed it out with the garden hose. Dumped it out, drained for 1/2 hour and installed with new filter. That was two years ago and my wife drives it every day in the summer.

 

Just did the same thing with my 510. So far so good.

 

Also, about using muriatic acid..........We used to use that at the metal shop to make things rust instantly, for decorative purposes. I cant imagine youd want to put that in a tank. Makes stuff rust FAST and BAD.

 

Most of the crap in my tank didn't look like rust anyway, it was the old inner coating flaking off(like black paint flaking off in tiny particles) under that was fairly clean metal.

[datzenmike]

Wiki:

 

Pickling of steel

 

One of the most important applications of hydrochloric acid is in the pickling of steel, to remove rust or iron oxide scale from iron or steel before subsequent processing, such as extrusion, rolling, galvanizing, and other techniques.^[6][18] Technical quality HCl at typically 18% concentration is the most commonly used pickling agent for the pickling of carbon steel grades.

[cdub42]

i would drop the tank, remove the fuel sensor, fill it 1/4 full of pea gravel, and then shake it till your arms fall off. hand it to a friend, have him do the same. rinse with water, then isopropyl alcohol or acetone. seal the tank with this stuff...

http://shop.lancair....C-79343CDB7869}

[ISPKI]

I thought muriatic acid was designed to clean off material that clings to steel, including rust. We primarily use it at work to clean electron beam deposition off of the insides of our welders. It works very well, but, if you do not dilute the hell out of it afterwords, it will rust everything around it.

 

I had another question. Are the gas tanks on these vehicles wide open inside? I know some tanks have champers or baffles what would cause stuff to get stuck and will make it difficult to clean, but I cant really see into the tank very well.

[VintageRice]

Mine has baffles. Stock 510 tank I'm pretty sure.

[datzenmike]

Shake it in all positions. Roll it around on the lawn.

[ISPKI]

I dont have a lawn, but I get what you are saying ahaha

[slowmomiata]

3 gallons of cider vinegar, some small gumball sized rocks, a bottle of berryman b12 stuff, and 2

gallons of distilled water.

 

then fill all the ingredients in the tank seal up the holes, put it in the back of a truck and

drive around for a half hour to an hour, slosh it around by hand shake it... anything

you can do to get the rock swishing and vinegar splashing.

 

after some time empty all the contents and rinse out with a garden hose, flush all that 

crap out and there is gonna be alot of junk pouring out.

 

reach in and get the rocks by hand or shop vac, i was amazed that i saw bare metal

after cleaning mine this way, plus its a fairly cheap method, i spent about 15 dollars

total at walmart

[cdub42]

3 gallons of cider vinegar, some small gumball sized rocks, a bottle of berryman b12 stuff, and 2

gallons of distilled water.

 

then fill all the ingredients in the tank seal up the holes, put it in the back of a truck and

drive around for a half hour to an hour, slosh it around by hand shake it... anything

you can do to get the rock swishing and vinegar splashing.

 

after some time empty all the contents and rinse out with a garden hose, flush all that 

crap out and there is gonna be alot of junk pouring out.

 

reach in and get the rocks by hand or shop vac, i was amazed that i saw bare metal

after cleaning mine this way, plus its a fairly cheap method, i spent about 15 dollars

total at walmart

great idea, but remember you have to re seal the metal

[slowmomiata]

i missed that step in the fair lady...

[72240z]

Not sealing just allows the tank to rust back up even faster. 

Take the tank to a rad shop and have them hot tank it, then seal the tank with a kit like the one from por. For the few bucks it costs to hot tank its so not worth breaking your balls with all this acid and rocks bs. 

[tybee260]

I did the POR-15 fuel tank kit about $50 from summit . My tank was FULL of rust and other junk, been daily driving my z for over 2 years since i sealed my tank with no issues

[Dguy210]

Last time I cleaned a tank (my 72' Mach1) I threw some big nuts inside and dragged it down to the DIY car wash. Washed it out with the high pressure water with intermittent shaking. I did do it late at night though in case anyone complained.

[Dawa]

my 620 had been sitting for at least 5 or so years

so i did the "add rocks and shake" thing followed by

oxalic acid, which is a lesser evil of all the acids listed as well as others.

after doing that shit, next time id rather just take it to a radiator shop or similar

and pay to have them clean it

[Pleadingbark]

What do you drain the gas into?  How much gas would be in it at about a quarter tank?

[Dawa]

i grabbed a 5 gallon bucket, put a t shirt over the top of it to act as a strainer,

and poured the gas into there. then poured the gas into an actual gas can &

reused it.

 

id say expect 3-4 gallons out of a 12 gallon tank at 1/4 full. idk the size of your tank

but if you go with my method you should be good.

[72240z]

Ya unless it comes out like varnish you can water it down with premium and use it. You can also use it to clean parts but I rather just use fresh premium for that. 

[Gery]

A line that drops down to the bottom of the tank (I assume it is the outgoing fuel line) has an expanded cylindrical section at the bottom end.  What is that? A filter?  Won’t it get fouled if I try to coat the tank?  

[datzenmike]

Bend the tube out of the way, coat and then bend back. Can't be a filter how would you clean it? and there is already a fuel filter at the engine.  

[Gery]

That’s what I was thinking but I always like to check with the expert(s).