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-   -   Drain tank or dilute old gas? (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/drain-tank-dilute-old-gas-1010645/)

TonyTurboII 09-05-12 01:52 AM

Drain tank or dilute old gas?
 
I'm in the process of doing a semi tune up on my car and was wanting some opinions on the old gas in the car. It's probably 3 or 4 years old and has some premix in it. Total amount of gas is unknown. The gauge is touching the line right above E.

Now it's getting kinda of hard to start, and I was thinking about putting in some new plugs and fuel filter in, and I'm on the fence about draining the tank (PITA), or diluting it with 10 gallons of fresh gas.

What do you guys think?

turboIIrotary 09-05-12 02:35 AM

I always drain old gas and use it for the lawnmower.

Rob XX 7 09-05-12 06:04 AM

You will not blend old gas and new gas. Drain it and be done with it.

Havoc 09-05-12 06:50 AM

dilute. ive done it for a 3.5 year sit. no problems

Tanj! 09-05-12 09:23 AM

I've done both. Draining it is your best choice as it gets rid of anything harmful that's brewed up including water. It's actually fairly easy if you go through the fuel pump hatch using a siphon kit that you can pick up at Walmart or Harbor Freight. I did zip tie a long socket extension to the hose in order to keep it standing upright in the tank and so the hose would sit at the bottom of the tank.

Should you choose to dilute it fill it with new gas and treat the entire tank with fuel stabilizer. The old gas is really past the ability of fuel stabilizer to help but it will also help trap any any moisture that's built up and clean up any immediate gunk. After you've run a few tanks through treat a tank with Chevron Techron Fuel Cleaner.http://contentinfo.autozone.com/znet...66362/image/4/

It seems to do a good job with any buildup in the injectors and crap that has built up on the fuel level float.

misterstyx69 09-05-12 09:38 AM

You are changing the filter anyways right?
Is it so hard to move to the back of the car and undo a 14mm bolt?
Quit being lazy and making excuses!!..(your car will thank you for it!)

Rob XX 7 09-05-12 09:43 AM

considering there is a DRAIN IN THE TANK, its begging to be drained.

if there is water it will not mix, if there is phase separation it will not blend.
What are we trying to save?

TonyTurboII 09-05-12 10:03 AM

My preference is to drain it, but I dont know if I have a container that will hold it all.

Im not trying to make a huge mess in my garage, and dont know what I would do with the old gas.

Rob XX 7 09-05-12 10:47 AM

you can literally leave it in a open container and it will evaporate over a warm weekend, if the line is just above E there cant be more then 3 gallons in there. Drain it into a 5 gallon bucket then take it to a oil change place and have them take it.

RotaryEvolution 09-05-12 11:57 AM

drain it out, filter it and use it in something like a honda.

Tanj! 09-05-12 01:47 PM

I've mixed old gas in with my waste oil and taken it to my local oil recycler.

p0tat0s 09-05-12 02:55 PM

Drain it. My turbo swap wouldn't start because of old gas came out completely brown when I drained mine. Definitely not good for the engine.

RotaryEvolution 09-05-12 03:13 PM


Originally Posted by Tanj! (Post 11211423)
I've mixed old gas in with my waste oil and taken it to my local oil recycler.

and they'll have a total shit fit if you do that and they find out. you will wind up with a bucket of crap you will not be able to get rid of.

the containers are not made to carry flammables, if they even smell a hint of gasoline they usually will refuse it.

don't do this, it's bad advice. you can use it as a solvent or in actuality it WILL dilute with old gasoline but it should be filtered and run in an engine that runs low compression otherwise it will knock. the octane of the fuel deteriorates over time. i usually filter it, mix it about 20% and run it in the non turbo 7 since they are very tolerant of even the lowest octanes.

TonyTurboII 09-06-12 01:09 AM

Thanks for the opinions, looks like i'll be draining it tomorrow.

Hopefully it all fits in the 15 qt drain pan i have.

spivey3 09-06-12 08:12 AM

I just did this. It's not too hard to put the plug back in while it's draining and switch containers. In fact, I would recommend it to avoid a pan that is full and weighs 45 lbs.

Rob XX 7 09-06-12 08:29 AM

i learned the hard way running old gas in stuff I thought could handle it, never again. Just not worth it.

I pump gas out of the boats all the time, look at it, smell it- think its good., filter it through a 10 micron water filter. I had a fuel pump and a carburetor lining corrode to the point I had to replace it, and in the bowl was brown crap. Meanwhile the thing had run GREAT for years, over 50 to be exact. Put some gas I thought was ok and it was like flipping a switch everything went to shit.

For years I had burned older gas in that old tug and it handled it, but get the wrong batch of gas just once and you are fucked.

TonyTurboII 09-06-12 11:32 AM

I dont plan on reusing the gas, lol.

Rob XX 7 09-06-12 12:41 PM

it makes for great weed killer, but the oil is what kills it

but im telling you leave it out and let it evaporate, it goes pretty quick

djphonics 09-06-12 04:16 PM

Please don't let it evaporate into the air

-Mother Nature

Rob XX 7 09-06-12 04:28 PM


Originally Posted by djphonics (Post 11212669)
Please don't let it evaporate into the air

-Mother Nature

yeah cause rotary fumes with 2 stroke oil in them are soooooooooo good for the environment, lol

we talking 2-3 gallons of gas he aint letting the exxon valdez evaporate into the atmosphere

jgrewe 09-06-12 04:34 PM

I had a friend give me this answer when I asked the same question.

How much milk do you need to add to bad milk before you can drink it?

Your car feels the same way.

TonyTurboII 09-06-12 09:54 PM

Well I got it all drained out. That shit took forever, and almost filled my 15qt drain pain.

If it ever stops raining here Ill leave it out to evaporate.

Got the fuel filter in as well, now to replace the plugs and a few cracked vacuum plugs.


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