LS - 1st and 2nd Gen (1990-2000) Discussion topics related to the 1990 - 2000 Lexus LS400

1991 LS400: How to drain old gas from the fuel tank. Ideas?

Old 05-27-08, 05:10 PM
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UofACATS
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Default 1991 LS400: How to drain old gas from the fuel tank. Ideas?

I have an LS400 that has been sitting for close to a year. I want to take a little precaution and drain the gas tank. It's half empty at this point (Half empty being the more optimistic term here ) I have a couple 5 gallon tanks waiting to fill, and an appropriate disposal.

Questions:

Will the cheap "hand pumps" at the local parts store drain a Lexus tank? They say on them, "one pump = one ounce" I think that will take some time, but if it works that's fine by me.

Can I unplug a fuel line and drain the tank that way? Where is there an access point?

Does the fuel pump activate at key "on?" Obviously for completion if the above question. This is the optimal procedure. It's easy on me and costs nothing.

Is there a better way to drain the fuel tank?



Thank you.
Old 05-27-08, 07:27 PM
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skperformance
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siphon hose like the old days .
Old 05-27-08, 09:24 PM
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Just get the neighbor kid to come over and start the siphon for 5 bucks?
Old 05-27-08, 09:47 PM
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dacecil
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The least expensive and best way to drain the tank is through the fuel injectors. While the engine is running. In other words, just fill the tank and drive it. The dilution will make the old gas less harmful.

Put a can of injector cleaner in at the same time.

The whole old gas thing is something of a myth. I have burned so called old gas in many internal combustion engines with no problems or side effects, as long as you don't give your engine only old gas. Again, the new will overcome any ill effects of the old.
Old 05-27-08, 10:01 PM
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I just witnessed a civic sit at the shop forever while the owners came up with the cash to fix the timing belt. Timing belt fixed, car runs great, gas is old and "bad," next morning car does not start. Valves stuck. Bad gas. Car back at shop.

So really, that experience is making me more paranoid than I normally would be. But, think of the consequences if the gas is bad?

Besides, less harmful? I really don't want to treat the car that way. Just want to drain the gas and start fresh.

Anyone know whether the fuel pump activates with the key on? I just haven't had the time yet to get it in the air and start looking for fuel lines, and really I'm not familiar and comfortable with my "new" LS400.
Old 05-27-08, 10:28 PM
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Thermactor
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that's liquid gold in that gas tank, just run it. jeez people have money to throw away these days
Old 05-27-08, 11:26 PM
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damon
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Siphon or let the pump electrically drain out the majority & then re-fill with 5-8 gallons of fresh fuel. Some cleaner would not hurt either.
Old 05-28-08, 09:08 AM
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SH212
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i think the best way to go is siphon.. thats what i would have done
Old 05-28-08, 09:32 AM
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Personally im super picky about what I put in our LS's...so id siphon it out myself if i had to. Id get a gallon of gas, put it in my tank and go fill that car up.

But old gas may not be as bad as the myth says it is, but old gas smells nasty when burned. So if it doesnt bother you to have a smelly exhaust for a few miles, just run it.
Old 05-28-08, 09:52 AM
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haulin79
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http://wiki.answers.com/Q/Can_you_mi...h_new_gasoline
Good stuff here.

Last edited by haulin79; 05-28-08 at 10:01 AM.
Old 05-28-08, 06:44 PM
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UofACATS
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Right on! Hey thanks fellas. The link is good stuff.
Old 05-28-08, 09:29 PM
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If you are worried add fuel stabilizer.
BTW old gas will never cause a damaged valve , the gas being old means it is less volatile so it will not start and the varnish is already inside the lines and tank. The reason the car above bent the valve was because the crook of a mechanic did the timing wrong so it crushed them , it is absolutely impossible for gas to bend a valve or cause any damage to it unless it ran super lean with a turbo . Gas being bad will just not fire.
Old 05-28-08, 10:56 PM
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Hmm. You might be right about most of that, really I don't know enough to argue so I won't. You're wrong about the mechanic though. Actually if you read that post again it says..

Originally Posted by UofACATS
Timing belt fixed, car runs great, gas is old and "bad," next morning car does not start.
Wrong timing leading to crushed valves does not wait until the next morning.

But, I'm not just trying to be right. Really I don't care about the civic or why it's broken, I care about my Lexus and keeping it not broken. That is all. Fundamentally, I am just being a bit cautious here (for the first time in my life.) I'm trying to prevent something bad that MIGHT occur.

It's 1/2 tank o gas. I didn't get a chance to go to the auto parts store tonight, so tomorrow it is. I'm going to pick up a cheap pump and pump/siphon it out.

Anyone who wants to come pick up the gas and put it in their lexus is welcome to stop by.
Old 05-29-08, 09:46 PM
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Too bad I don't live near you. ARRGGGH that's $40 of gold you're THROWING away
Old 05-29-08, 10:04 PM
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With a normal car it may be instant to not turn over to bend a valve if that is what in fact it did .
But Honda has a little thing called v tec so while the car is idled or not reved high the timing is not advanced enough to cause any piston valve slapping. As soon as the rpms raise and its is activated the valves start to bend. If the gas is old it may continue to run but not when cold as the compression is low from the valve being bent so it cannot fire.
Hope this makes sense. Either way the mechanic is a crook and should not be trusted with a donkey cart never mind a civic.

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