HOW TO: FLUSH GAS TANK (while still in the car)
 

I searched and searched and searched.... To no avail.. So I decided to try a bunch of stuff and see what works... I think I have the worst gas tank/fuel pump ever recorded...

I am working really hard to de-goop my tank.. It had been sitting for 10 years with 3/4 of a tank of gas, which had turned to varnish and basically gummed up the tank really bad.

My current process involves 7 gallons of e85 fuel (basically cheap ass solvent)... I poured it in the tank, and sloshed it around for a while, then let it sit for a few hours.. Then drained it, and repeated the process about 6 times.. I need to get more fuel as the stuff I have is way too contaminated now... back at it tomorrrow...

Anyone else ever dealt with something this nasty?? What did you guys do to solve it without spending $150 to clean/seal the tank?? I have $13.00 in e85 so far, and will do it again tomorrow.... Just time consuming trying to get all the grainules off the bottom....

See pictures for progress.... The tank looked like the fuel pump prior to the cleaning...

https://www.rx7club.com/attachment.p...1&d=1250996925

https://www.rx7club.com/attachment.p...1&d=1250996936

Wooh, that's a first for me. The only thing I can think of is some type of oil based cleaner or maybe some paint/lacquer thinner??? Find a brush (pic below) and scrub that crap good. If you have an old wet/dry vac laying around, use that to suck it up. Wonder what the fuel lines, rails, injector, etc. are like...

My .02, hope that helps.

Holy jeeeeez man! How is your engine even still alive?

When I swapped out the stocker fuel pump for a walbro last week, there wasn't even a spec of dirt to be found. Can't even believe it can get that bad.

+1

put gloves on and scrap the hell out of it then use Paint "removers'' or "paint stripper" (chemicals) You could sand it but yea..... lol

for the thick nasty gum in the tank, you might use a hot water high pressure washer or a steam cleaner to break that stuff loose. then get some air system dryer (found at truck stops usually) and use that to finish up wiping the inside out. You could also use plain old alcohol or acetone, but the methyl alcohol and other nasty stuff in it works best at dissolving gum and removing water
If youve never used air line dryer before be extremely careful, that Sht is really nasty to breath in, get on your skin is extremely flammable too.

Another thing you could do is get a gallon or two of mineral spirits (solvent).. whatever is cheapest and pour it inside the tank and let it sit. that gun will get pretty nasty but it will be easier to remove than with a scraper..

you might put your fuel pump inside a cup of regular rubbing alcohol too... i dont advise using anything else on that. methyl and over the counter solvent stuff will usually eat or weaken plastics. wouldnt hurt to run the alcohol through the pump on the bench either... good luck.. just be happy its gum and not rust and corrosion..
c

aww, that is freaking nasty.

hmm ... I wonder what my fuel tank is like ... will drain & check it some time next or next next month ... and replace the fuel pump witha walbro or something.

That black goopy stuff is what DSM guys are discovering on their injectors when they just dump in E85 and go.

To clarify, my Turbo engine has never run in this car. The car hadn't run since 1999 on the N/A engine that was in there. I sprayed carb cleaner down the fuel lines and caught the fluid that came out.. It was dark, so i ran fuel through the lines and let it sit, then blew them out again with compressed air..

Fuel pump- I have a new T2 fuel pump that I will be using, the other pump is soaking in fuel and I actually got it to circulate fuel again last night.. pretty amazing

As for the tank.... I have never seen worse.... I have had 27 rx-7's and never seen worse..

so thats what 10 year old gas does.

think about replacing the tank at $100 http://cgi.ebay.com/ebaymotors/86-91...#ht_3519wt_939

also try things like local part outs and autoparts stores like car quest or olympus

SO e85 mixed with reg pump gas will cause it to tar like that?

at that point i would drop the tank and take it to a shop that specializes in tank cleaning. this way you will know that it had been dipped and boiled out until clean. it might cost you a few bucks but in the long run its worth it. i have an FB tank thats like that. yours is just plain awful though.

Not really sure about that... E85 cleaned my tank...

yeah man drop the tank shouldnt be too hard, a weekend project.. if you have a pressure washer blast it, or if you have access to one .. lol.

or go late at night to a do it yourself car wash and use theirs? lol

No, the old gas caused the tarnish. The E85 cleans it away, but it ends up later in the fuel system eventually.

better off having a professional empty the tank...I know its hard to clean it out for welding.. I would just get another gas tank//.. a empty gas tank is the most dangerous than afull gas tank, it may not look liek it but theres still vapor gas in there and if something ignites boommm....

with the amount of wrecked FC out and all these wanna be drift kings, i am sure you can find a gas tank pretty cheap - if not free...
i just replaced mine and trust me, mine was even worst than that with 10 years old gas.
infact, it was so bad it stunk the car up so it smelled like a farm in there.
wasn't until that i decide to take the fuel pump out till i found out what was in it....
the last owner said he drained it.... guess he didnt.

there are all sorts of Chemicals out there to clean the innards of a tank.I feel ya,not wantin to drop the damn thing.Why?If you have a BIG hole Up top,with access to the Inside of the tank?.Right??,and it's got a Drain plug on the bottom of the tank, so you can clean and drain it.
My suggestion is TPS(trisodiumphosphate.) paint Department.
wear gloves.wash the inside of the tank with a Dilluted mix of this and then Rinse out with Gas..wipe out.
That is about the cheapest route to go..you should be lookin at getting all new lines and a Pump,and new fuel Filter at the engine,so the New gas will not encounter old Crud.

Hey RRtec, there is a thread on here that helped me whe i was doing this but can't seem to find it. my gas tank was in much shittier conditions since it sat for 4 long years. but what i did was drop the tank (which isn't hard a all), drained whatever fuel was in there, pour murric acid (this shit is really strong so try not to get it on you). let it sit for about a 5-10 minutes and repeat the process a few times till its gunk free at the bottom. also dont let it sit to long in there cause you dont want it to eat through the tank. After that i pour water in there to remove the remaining acid out and put my gas tank inlet holes next to a cars mufflers to dry it out with the cardon monoxide or you can use a heat gun (I did both cause the welder didn't want any fumes in it what so ever cause of a bad exprience he had with an impropery cleaned tank!). That process took about 30 or so minutes to make its all dry. Well the oily gunk build up i had was covering a hole i had at the bottom of mine but got it repaired by a dude that welds gates?(which wasn't easy to find if i might add) all in all its not the hard to do. Oh, i forgot to mention that when you are dropping the tank. don't foget about this vent that sits on top of the tank. Its connected to a small hose which can break very easily. Hope this helps eventhough you dont want to remove it from the car


Greg

I'd drop the tank and have it boiled... but that is me...

This is encouraging! I have a truck thats been sitting for 20 years with an unknown amount of gas in it.

It looks like your on the right track, good luck.

Whenever I get motorcycle gas tanks like this that are rusted out + varnished like this I use a product called Kreem. It's a 3 stage process. There's an acid to clean out the varnish/rust, then a rinse + an epoxy type material used to coat the tank to prevent rust from forming again. Only problem is that sometimes the epoxy will come loose from the inside of the tank, then clog shit up.


So I think the cheapest + quickest way for you to go is to get a new/used tank off ebay etc. Then buy yourself a new fuel pump. Maybe upgrade to a walboro.

Yeah, "lol" indeed.
Don't do it.

My brother owns several car washes and if you tried this at one of his, he'd prosecute you.
The return water from a car wash is carefully monitored by the city treatment plant...they know when something foreign gets dumped down the drain.
All his bays are video monitored, so it's be easy to find the culprit.
The fines can be quite high, so it's not worth the risk.

Many radiator repair shops are also set up to clean fuel tanks...let them deal with it.

This is how my FB in-tank filter looks like right now and the nasty stuff that's coming out of the tank. I still can't find a replacement in-tank filter and nobody on that thread is answering me back about it. But I'm basically in the same boat :(.

Rotabimmer clean it the best you can then cut the filter off and use an inline filter. If your tank is just as bad you have to scrap it by han and use solvents. I'm a huge fan of POR 15. I
On my phone so forgive me if the link dosent work. Fuel System Restoration-POR-15 Inc.