What To Do About Year Old Fuel In Tank ...
 

This car I am about to pick up (1993 RX7 TT) has a blown motor and been sitting around for about a year or so under a cover. So now I thought to myself today, you use fuel stabilizer if your going to store something for 2 months or more. Since its been 6X the minimum, I'm starting to have concern about the state in which the fuel is in. I figure I can siphon the fuel in the tank and replace it, but what about the gas in the lines? Do you think I have to get the fuel injectors cleaned, or should i just upgrade them while i am at it? Fuel System Cleaner?

The fuel tank has a drain plug under the car. No need to use a siphon. Don't worry about the fuel in the lines. It won't be a lot. If the engine needs to be replaced, then yes, go ahead and have the fuel injectors cleaned and flow balanced. It doesn't make sense not to do it at that point unless you know for a fact that they have been recently cleaned.

General rule of thumb is that if the fuel doesn't smell like paint thinner, then it is good.

Just run it...but don't go doing WOT runs under full boost if you're paranoid.
I've used 2 year old gasoline with no problems.
You can drive down to the closest gas station and fill up on premium stuff to dilute it down, but the engine should have no problem burning that stuff now.

It's more a pain to "get rid of" old fuel.
I had to ditch about half a tank of gas by burning it in an open field...
Oh shit that was major dangerous!

I don't need to go into how much more dangerous it is to pour it down the drain or into the sewer system...


-Ted

Well my next question was gonna be ... where do i dump it? I lit about a gallon of gas one time in the street ... yeah ... NOT a good idea ... , and i'm not about to dump it into the sewer ...

I was just curious cause you generally hear old gas being refered to as something that is gumed up ...

I think imma drain it just to be on the safe side, clean the injectors ... run fuel system cleaner in the tank once, maybe twice ...

If you drain it, just use it for gas powered lawn equipment (lawn mowers, blowers, weed eaters, etc). If its only been in there for a year, it should be fine. After 2 years, I'd be a little more concerned.

Yeah, use it on lawn equipment or a generator, don't dump it.

I Was Able To Find This Info ...

The fuel system is going to require specific attention. As fuel sits, it begins to decompose. After a while it looses it's potency and becomes stale. If it continues to sit for long periods of time it will dry out and either gel or become a powder (depending on how long it sits). If the drain plug on the bottom of the tank can be removed (they are normally rusted in place) use it to drain any remaining fuel from the tank into an approved container. If this plug isn't an option then you'll have to siphon (don't use your mouth to create suction). If the fuel looks at all like it was in an advanced state of decomposition (very yellow, floating sediment) then the tank itself will probably need a cleaning. Beside the drivers shock tower in the rear of the car is an access panel through which you can get at the fuel pump flange. It's highly likely the retaining screws will be rusted so have fun removing them. Plenty of penetrating oil and an impact screw driver are a definite necessity here. Once the pump assembly is removed (pay attention to the condition of the rubber fuel hoses and replace if necessary) you can get at the inside of the tank with a rag-on-a-stick to remove as much gunk as possible. Afterwards, reinstall the pump assembly using a new gasket and new hose clamps. Fill the tank with several gallons of fresh fuel mixed with injector cleaner (the cleaner is largely ineffective but you might as well use it as it may help out a little). Now you can move to the front of the car and begin to flush out the lines. The first step is to remove the fuel filter and attach a section of rubber fuel hose to the metal line. Place the other end of this hose in an approved container. To run the pump, you will need to jump the diagnostic connector at the passenger front shock tower. It's a yellow plug with two connections and you can jump it with as small jumper lead or even a paper clip. Watching your fuel hose carefully, set the key to IGN and allow the pump to run until fresh fuel flows from the hose. At this point you can shut the car off, remove the jumper lead and install a fresh fuel filter in place of your temporary hose. Now some stale fuel will still remain in the fuel rails so you can pull the upper intake an fuel rail assembly to give things a thorough cleaning if you have the equipment and supplies handy. Most of the time this is unnecessary as the new fuel will flush out old contaminates.

That's all find and dandy, but what it didn't tell you was how long it takes for fuel to decompose. ;) Unless the car has been sitting for many years, just do as everyone has suggested in this thread.