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1989 Fleetwood Brougham d'Elegance|2018 Chevy Colorado Z71
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Discussion Starter #1
Took my 89 out of winter storage recently and it's got a tank of spoiled gas in it. The car's performance is bad, idles rough, and can sometimes stall out when driving. This tends to be remedied by adding a decent amount of high octane fuel to the tank, but that means I have to keep burning off what's in there in order to make room for newer more potent fuel. I don't want to purge the system, I just don't have that kind of time to do that during the week. What I'm looking for is some kind of solution to my problem that I can pour into the fuel tank. Anything that will reinvigorate the existing fuel? It's pretty much 3/4 of a tank and I'm trying to burn it off as quickly as I can.
 

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2008 DTS PERFORMANCE GONE (R.I.P.)
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1,160 Posts
I've had that before, gas stabilizer is a must for long sits. ---------- I
would try some Lucas fuel stabilizer to try and take some of the water out of your fuel. It helps with the effects of "bad" gas. I used it and it seemed to help,
 

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87 Brougham, 1969 Calais, 95 FWB, 07 SRX, 07 ESV
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4,246 Posts
You could try adding some octain booster or fuel stabilizer stuff to see if that will help. It might raise the octain faster than mixing in fresh fuel. I'm not sure as I've never parked my cars with that much gas in the tank.
Usually I run them down low before winter and then top it off with some fresh stuff on the first drive of the spring.
 

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1989 Fleetwood Brougham d'Elegance|2018 Chevy Colorado Z71
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Discussion Starter #4
You could try adding some octain booster or fuel stabilizer stuff to see if that will help. It might raise the octain faster than mixing in fresh fuel. I'm not sure as I've never parked my cars with that much gas in the tank.
Usually I run them down low before winter and then top it off with some fresh stuff on the first drive of the spring.
Yeah I usually do as well but someone convinced me filling the tank and tossing in the stabilizer was a better way to prevent moisture from building up in the tank. Lesson learned. I put a bottle of Lucas in the tank last week and it helped in the moment but the gas went bad again while the car was parked for a few more days. I'm gonna try the octane booster and see how fast I can get down to a half a tank before throwing any more new fuel on top of it. I'm at 3/4 tank now.
 

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2014 ELR
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Forget the octane booster. Just keep putting in fresh gas and drive it. Get ETHANOL free if you can. How old is the gas?
 

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1989 Fleetwood Brougham d'Elegance|2018 Chevy Colorado Z71
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6,421 Posts
Discussion Starter #6
Forget the octane booster. Just keep putting in fresh gas and drive it. Get ETHANOL free if you can. How old is the gas?
About 5 months. I bought a bottle of Lucas octane booster that would treat up to my max so let's see what this does to the fuel that's already in the tank. I'll fill up once I've eaten away another quarter tank or so. I doubt any of the gas in N. Jersey is ethanol free but I usually visit the big names for fuel. Gulf, BP, Sunoco, Shell, Exxon, etc.

I intend to daily the car for at least this week. I hope I'm not doing any damage to my 307 driving around like this......
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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"Octane boosters" raise fuel octane by X points - as in: 87 octane to 87.2 octane. Read the fine print: "May raise octane by several points ......".Waste of money. Want octane boost ? Take a 5 gallon jug to a local small airport and fill it with 100 octane avgas. DO NOT habitually run avgas - it contains some tetraethyl lead and that just kills catalytic converters.

There is no reason that fresh fuel, especially a Top Tier fuel, treated with gasoline stabilizer (marine stores) should not be as good after 5 months as it was when you pumped it in. Do all your lawnmowers and tractors crap out after a winter storage ??? .......... and, yes - store a car with the tank full of treated gasoline. Excess airspace in the tank causes moisture from condensation due to expansion and contraction - venting.

Top Tier gasoline and Chevron TECHRON. Google them.
 

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2014 ELR
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Five months is not old gas. Just keep driving. You can find the closest ethanol free gas on pure-gas.org, but you should have no problem at all running five month old gas.
 

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1980 FBC
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980 Posts
Just drove my 21 year old Mercedes 150 miles round trip in 7 month old fuel. Only problem was it got 19 MPG instead of 22.

The fuel didn't smell sweet so I didn't worry.

Really stale gas varnishes the engine innards. Do not ever use it for even a minute.

The only thing octane booster does is slow the rate of fuel burn so you can run with higher peak combustion pressure.
 

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1991 Cadillac Brougham D'Elegance 5.7 Litre, 1994 DeVille
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6,796 Posts
If it's just 5 months old the gas should still be good. Just keep topping it up with good stuff till whatever problem it is works it's way thru.
If the carburetor hasn't been touched in a while it could very well be something wrong with it that's causing your problems.
 

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1970 Coupe De Ville//Cessna 172
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551 Posts
Probably have some water in the fuel. It will settle to the bottom of the tank. In the airplanes we have quick drains at the bottom of the tank for that reason....... But not for cars. Fuel and water is probably mixing as the fuel sloshes around in the tank. I would not let the tank get too low or you could end up with a higher ratio of water to fuel and get to the point where she won't run.
Jeff
 

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1992 Fleetwood S&S Hearse, 1993 Buick Roadmaster
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567 Posts
My car sat for 5-8 months before I bought it, with maybe half a tank in it. I filled it with 91 octane gas (what it calls for) and a couple little bottles of "water remover" product. People will argue until they're blue in the face about what is/isn't worth buying, whether any of it is anything more than "snake oil," and all that. But what I did worked well for me!
 

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1989 Fleetwood Brougham d'Elegance|2018 Chevy Colorado Z71
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Discussion Starter #13
Wore it down to half a tank and filled it with BP 93 octane. Drove a few miles home, no noticeable differences so far. I'm guessing it'll take a while to work itself out?
 

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1979 Coupe deVille, 1995 Sedan DeVille (sold)
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Your problems are with ethanol and moisture. I don't see how higher octane is going to help with that.
 

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1989 Fleetwood Brougham d'Elegance|2018 Chevy Colorado Z71
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Discussion Starter #17
I added both of those chemicals to the tank already, and there is potentially 1 filling station in NJ that sells 100% pure gasoline and the place is almost 2 hours away. The best thing I can do is apparently keep dumping E10 fuel on top of it.
 

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1980 FBC
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980 Posts
Sounds like the engine may need attention and the problem was not gas. Maybe some critter ate a chunk of vacuum line.

Too much water remover will kill the accelerator pump in a clodrajet.

They don't hold up well with today's "gasoline" anyway.
 

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87 Brougham, 1969 Calais, 95 FWB, 07 SRX, 07 ESV
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4,246 Posts
It's easy to miss one vacuum hose in the miles of them in these cars. Glad you found yours!
 
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