how long can gas sit in a car and still be fine?
 

so i had to go out of town for about 2.5 weeks left the car sitting on the street ran just fine before the trip, (had about a quarter tank, if it counts for anything) but now just took about a 40 mile and i noticed the when im coasting like not pressing on the gas just letting the car take itself it boggs or surges whatever you wanna call it. sounds like it wants to die then it revs up and keeps doin the same thing. when i am completely stopped it doesnt do it. hasnt died on my or anything yet but came pretty close.
been reading a couple of posts with similar problems but im leaning towards bad gas?? the car usually runs rich before the problem.
any suggestions welcome. i did put 2 more gallons of gas before the trip.

i recently changed a coulple parts within the past 3 months:
spark plugs and wires
fuel filter
distributor cap and rotor
and oil change

:help:

Re: how long can gas sit in a car and still be fine?
 

bump

Re: how long can gas sit in a car and still be fine?
 

6 months id say for fuel. The engine carbed? Fuel injected?

Re: how long can gas sit in a car and still be fine?
 

I've ran gas that's been 3 years old.
Is it good for the injectors and stuff. NO
Is it still volatile enough to burn YES.

At work Im in the middle of a delorean restoration cars been sitting for 2 years. got it to run when it showed up on 2yr old gas. to check everything out. Then pulled the tank and cleaned it all out. pulled the FD apart and cleaned it out.

As gas sits it doesnt loose it ability to burn properties in it evaporate and it starts to gum up. Thats whats bad for the fuel systems. It gums everything up.

Re: how long can gas sit in a car and still be fine?
 

After 2 1/2 weeks, the gas is still good, so i would rule that out as your driveability problem. Gas should last 6 months, but with the Ethanol content these days, shelf life is likely much shorter. If you know it's gonna sit for a while add some stabilizer.

Re: how long can gas sit in a car and still be fine?
 

2-1/2 weeks is nothing. The fuel should be fine. If there's any doubt, remove the filler cap and give the filler neck a sniff. If it smells like paint thinner the fuel is bad.

Honestly, I'd look elsewhere for your problem.

Re: how long can gas sit in a car and still be fine?
 

Unless it's AV gas, that is.

You'll know bad gas. Smells like varnish.

Re: how long can gas sit in a car and still be fine?
 

I've left 91 octane in my Nova for 4 weeks at a time between driving it and it's fine.

Re: how long can gas sit in a car and still be fine?
 

You left the car sitting on the street???? How do you know someone didn't pour water or worse in it?

Re: how long can gas sit in a car and still be fine?
 

What could be worse than water.....never mind. :p

Re: how long can gas sit in a car and still be fine?
 

Could be something as simple as a clogged fuel filter. When was the last time you changed that? It should be done with any tune-up. Its cheap and takes just a few minutes

Re: how long can gas sit in a car and still be fine?
 

i have replaced the fuel filter recently, i doubt its clogged already, i also replaced the battery. would bad timing do any of this?? also when i got back from my trip my aftermarket stereo was reset like i f the battery had been disconnected. im gonna try to look for vacuum leaks and try an idle relearn
how do u check an alternator??

Re: how long can gas sit in a car and still be fine?
 

its fuel injected

Re: how long can gas sit in a car and still be fine?
 

Bad timing can affect all kinds of things. I could definitely see that as a possibility. How is the transmission doing? does this only happen in 4th gear? You could possibly test throwing it in neutral when you see it happening and see if it continues. If it keeps doing it, I'm thinking engine issue of some kind, if it stops I'm thinking trans. Could be all kinds of things. was it not doing it before you left for your trip?
As far as testing the alternator, I'm assuming your car has a battery gauge. What does it read?
http://www.wikihow.com/Check-an-Alternator
thats a link to a step by step alternator check.

Re: how long can gas sit in a car and still be fine?
 

the battery gauge reads fine ill keep an eye out for it tho. and no it wasnt doin it before my trip when im goin over about 15 mph it doesnt do it the trans is still good rolls through all the gears nice and smooth. havent cheched the neutral thing tho, i drove the freeways just fine its only when im cruising real slow.

Re: how long can gas sit in a car and still be fine?
 

Ive had half a tank of gas in my Camaro for almost a year. Every once in awhile, Ill turn on my camaro just to keep the upper engine lubricated. So you should be good.

Re: how long can gas sit in a car and still be fine?
 

oh alright I was thinking it was at higher speeds. I had something like that happening and I'm pretty sure it was the lockup on my torque convertor giving out. never did figure it out for sure though I sold the car before I could haha. Well, I guess I would go back to starting with basics again. check the timing, throw a vacuum gauge on there, maybe even a fuel pressure guage, and see what comes up with that. Do a visual inspection too(spark plug wires, vacuum lines, basic stuff like that).

Re: how long can gas sit in a car and still be fine?
 

turns out my intake came loose i dunno how havent messed with it in a long time. im thinking i still have a leak somewhere else too cause it still surges a bit very very lightly, whats a good way to find leaks? i cant physically see any loose or cracked hoses

Re: how long can gas sit in a car and still be fine?
 

intake cleaner. spray it along vac lines & around the intake. If the engine bogs down, you found your leak.

Re: how long can gas sit in a car and still be fine?
 

Quick was is Carb cleaner in a spray can. Spray all potent leak areas.
Proper way is a smoke machine to pump smoke in and look for leaks.

Re: how long can gas sit in a car and still be fine?
 

ok i probably try both, would a fog machine like for halloween work or is that just a horrible idea?? and will the carb cleaner eat through anything or anything i should avoid spraying?? thanks evary1 for all the replies

Re: how long can gas sit in a car and still be fine?
 

91 octane can last years and it be burnable.

Re: how long can gas sit in a car and still be fine?
 

brake clean , carb clean, will all work.
I guess you could make a Halloween for machine work somehow. Prob. put out way to much smoke to push thru a small hose.

Re: how long can gas sit in a car and still be fine?
 

It could also be a fuel pump or suspect fuel lines? Clogged fuel injectors could cause surging too but somehow you have to diagnosis it without buying all new parts.

Re: how long can gas sit in a car and still be fine?
 

yea dont really want to throw a bunch of money at it and hope for the best. there are no codes bein thrown out either. ive been having problems with a brand new battery. you think maybe the alternator?? my volts read past 13 wich is weird. its more like 15 dunno whats goin on there.

Re: how long can gas sit in a car and still be fine?
 

My 2nd gen Trans Am has or had half a tank or at least that's what the gauge reads, of Gas from 1986. I don't dare to start it like that tho, I'm afraid to break something, and I wonder if there's even gas left that it hasn't gummed up, I poured half a bottle of fuel stabilizer in it about 3 years ago but I don't know if that did anything to 20 year old gas :-\ but gas should last a good 8 years so that you can start the car, I did so with my Mercedes and Oldsmobile, Mercedes been parked since 2005 with 1/4 tank of 91 Premium started it back in '09 with a new battery, 3 cranks later and Vroom! only drawback was a lot of black smoke came out of the tailpipe at first then immediately after some light grayish smoke looked & smelled weird like Carbon Monoxide, my Oldsmobile started with the same new battery after 7 crank tries being parked since 2002 with 1/4 tank of 87 Regular started it up for the first time in 8 years in 2010, so I know gas is still good flowing at 8 years old, but I only had to move the car a few hundred feet, next year sometime I plan to turn it on take it to the Nearest station and burn out the remaining old gas and put new 91 Premium in it followed by a MAJOR much needed Tune Up.

Re: how long can gas sit in a car and still be fine?
 

Autozone or Advanced Auto Parts can check your alternator to see if it's good or not. I never used the tools myself to know what the reading are supposed to be.

I'm fairly sure that automotive fluids are not supposed to be stored more than one year.