Bad gas??

Discussion in '1965 - 1973 Classic Mustangs -General/Talk-' started by colt65, Jan 6, 2004.


  1. colt65

    colt65 Founding Member

    Joined:
    May 31, 2002
    Messages:
    142
    Likes Received:
    0
    Trophy Points:
    0
    Ok anyone know when gas goes bad? I tore the car apart about a year and a half ago, just put it back together, and it's not running quite right. Before I tear my webers apart and rejet the whole enchilada, I was thinking that maybe the gas in the tank had gone bad... any ideas? I put about 11 gallons in on top of the old stuff (about 1/4 tank) and it still ran bad, but that may be that the new stuff stayed at the top of the tank. :shrug:
  2. charlies

    charlies New Member

    Joined:
    May 1, 2002
    Messages:
    402
    Likes Received:
    0
    Trophy Points:
    0
    my experience has been that bad gas has a distinctive smell. 2 times, gas from mustangs that sat for years. they both smelled the same, a kerosenish or shellacish smell. quite distinctive from normal smelling gas.
  3. Platonic Solid

    Platonic Solid Founding Member

    Joined:
    May 29, 2002
    Messages:
    1,966
    Likes Received:
    1
    Trophy Points:
    39
    Siphon some gas out with a hose long enough to reach the bottom of the tank. Gas sepparates into 2 parts. The top part looks like regular gas. The bottom looks like milk. I learned this the hard way. The only solution is to drain and flush the tank and lines completely.
  4. HistoricMustang

    HistoricMustang Active Member

    Joined:
    Apr 11, 2003
    Messages:
    2,363
    Likes Received:
    0
    Trophy Points:
    46
    Spend a buck or two and always use "Stabil" if the car is going to sit up a month or two or longer. Otherwise you have varnish.

    In my race rod I put in a squirt or two between each race.

    HistoricMustang
    www.historicmustang.com
  5. colt65

    colt65 Founding Member

    Joined:
    May 31, 2002
    Messages:
    142
    Likes Received:
    0
    Trophy Points:
    0
    What does this mean? <gulp>
  6. colt65

    colt65 Founding Member

    Joined:
    May 31, 2002
    Messages:
    142
    Likes Received:
    0
    Trophy Points:
    0
    Ok, so what's the best way to REMOVE the varnish?
  7. pabear89

    pabear89 Active Member

    Joined:
    Apr 16, 2003
    Messages:
    2,126
    Likes Received:
    0
    Trophy Points:
    46
    Drain, tank and remove.
    pour in Shot from 2- 12guage shotgun shells and about 24 oz of gas and shake the thing like a marocca. :rlaugh:

    It will remove even rust from inside a tank.
    Empty shot and rinse with clean fuel and install.

    For Fuel lines, I have sprayed carb cleaner in them to loosen any blockage and blow out with compressed air.

    PB

    Ps. If the gas has turned and you added new fuel, give your filler hole a smell.
    And if it does not smell like the fuel that you put in your daliy driver, Or like it's flat or spoiling egg smell. then it's turned. :notnice:
  8. SandSprite

    SandSprite New Member

    Joined:
    Feb 9, 2003
    Messages:
    332
    Likes Received:
    0
    Trophy Points:
    0
    Don't use shot from a shotgun, unless you count each ball. You could easily lose one or leave one in to cause problems. I hear a light chain works well.
  9. Platonic Solid

    Platonic Solid Founding Member

    Joined:
    May 29, 2002
    Messages:
    1,966
    Likes Received:
    1
    Trophy Points:
    39
    I did just as you did - poured lots more good gas on top of bad in my 72 coupe. Then drove it to work (almost), but it died 3 times within 10 min. of driving. It would idle fair, but once things got moving, it would choke and die. Finally got stuck on the highway. Got my AAA moneys worth that day.

    After replacing the fuel filter about 5 times, I disconnected the fuel filter line and turned to engine over and let it pump gas into a jar. That's when I first saw small milky globs. Getting the 15 gals of gas in the tank out was a real PIA since mine doesn't have a drain plug. I ended up purchasing a new gas tank (yet to be installed) since my other one was somewhat rusty inside and dented anyway. Plus, new tanks aren't very expensive.

    I'm currently running the car with a hose into a gas can (no, I don't drive anywhere that way). That allowed me to purge the fuel lines - plus I blew them out with compressed air.

    I also need to rebuild the carb. since the car still runs like crap.
  10. Pakrat

    Pakrat Founding Member

    Joined:
    Aug 6, 2000
    Messages:
    3,856
    Likes Received:
    0
    Trophy Points:
    56
    Just to quickly answer the first part of your question, gas has a shelf life of about 30 to 60 days without some type of stabalizer added to it. Every spring and winter I get 4 or 5 neighbors who come to me and say "Hey, your good with engines, why can't I get my lawnmower or snowblower to start or stay running? Could you look at it?" My first question is always "Did you remove or stabalize the gas at the end of last season?" And 95% of the time the conversation is over and problem solved on the spot. I usually just get a turkey baster and drain out the gas, add carb cleaner and new gas and they are good to go. If you can drain the tank, the same may get you by, just keep adding a small amount of new gas and carb cleaner and run the car until it is dry. In either case, get in the habit of adding stabil or some type of dry gas between extended down times once you fix it if you continue to leave gas in the car.
  11. HistoricMustang

    HistoricMustang Active Member

    Joined:
    Apr 11, 2003
    Messages:
    2,363
    Likes Received:
    0
    Trophy Points:
    46
    Pakrat has got it.

    Also, If you are to the point of having varnish, you first need your butt kicked (unless you purchased the old girl).

    To get it straight you need to tear it apart and do the old girl some good.

    Who wants a crappy running ride!

    HistoricMustang
    www.historicmustang.com
  12. colt65

    colt65 Founding Member

    Joined:
    May 31, 2002
    Messages:
    142
    Likes Received:
    0
    Trophy Points:
    0
    Thanks for all the help guys.

    Ok, yeah I'm *sort of* an idiot. My car wasn't supposed to take a year and a half to get painted, it was only supposed to take 2 months - :notnice: So I never got a chance to go in there and add any Stabil or drain the tank, etc.

    So here's the latest. I only originally had a 1/4 tank of bad gas in the tank. By the way, I should mention I have a foam/plastic fuel cell, all aluminum fuel line, and AN fittings/stainless braid where there's not aluminum line. Ok, so with the 1/4 tank in there, I added about 10 gallons of fuel on top of that. It ran like crap, so I added the Stabil, which I don't think did much good, since you're supposed to add it BEFORE you store it (preventative) -- thats the part where I'm an idiot. So I took it out last night around town, and drove it pretty hard... now for those of you who know anything about webers... it idles decently well, but the main circuit (2900 RPM plus), acceleration, and the transition (26-2900 rpm) is pretty bad. Generally, there's very little torque, it pings on acceleration (even after I retarded it a bit), and runs generally bad. The O2 sensor gives me the impression I'm running a BIT leaner than I used to, but not entirely too much.

    The question becomes this - now that I have 14 gallons of fuel in the thing, should I just keep running it around town until I go through the whole tank, add more gas, some carb cleaner, and hope for the best, or should I just empty the tank into several 5 gallon drums, take it to the local gas station and recycle it? I looked into the tank with a flashlight (not a match) and there didn't seem to be much in the way of "milkyness" -- it looked decently clear. I didn't siphon it out to have a closer look, but maybe I should do that?? Your help, as always, is appreciated...
  13. HistoricMustang

    HistoricMustang Active Member

    Joined:
    Apr 11, 2003
    Messages:
    2,363
    Likes Received:
    0
    Trophy Points:
    46
    Get the bad stuff out. Your tank is kind of like a swimming pool. Once someone takes a "wizz" in it, it ain't no good no matter how much you work with the water.

    HistoricMustang
    www.historicmustang.com
  14. pabear89

    pabear89 Active Member

    Joined:
    Apr 16, 2003
    Messages:
    2,126
    Likes Received:
    0
    Trophy Points:
    46

    What does not shake out of your oversize morrca, can be removed thu filler hole with a flexable shaft magnet tool. :)


    Did you go to the SLO Car show last august?
    you might have seen mine parked with the CarCraft Road trip group.
  15. 3spd on floor

    3spd on floor Founding Member

    Joined:
    Aug 13, 2002
    Messages:
    1,102
    Likes Received:
    0
    Trophy Points:
    0
    i only had one experiance with bad gas, it was in an OLLD lawnmower engine, we're talking late 50's old. the kind that had a horizontal shaft motor and shear style blades, like the ones on the old push-rotary mowers. anyways, we were puttin it on my go cart. couldnt even get it to put on the old gas, drained it, blew the varnish out of the fuel pick up and she roared to life in one pull.

    always try the cheap things first.
  16. SandSprite

    SandSprite New Member

    Joined:
    Feb 9, 2003
    Messages:
    332
    Likes Received:
    0
    Trophy Points:
    0

    Nah, I wasn't around in August. I'm only here for school (Cal Poly). Which show was it? I try to make it to the shows up here, but I never show my car (not worthy yet).
    --Tim
  17. Great68

    Great68 Founding Member

    Joined:
    May 17, 2002
    Messages:
    707
    Likes Received:
    0
    Trophy Points:
    0
    My experience with bad gas was with my friend's 350 powered Jeep YJ. One day it started idling REALLY high, like 1200-1600 rpm. We looked for vacuum leaks, played with the timing, adjusted idle speed and mixture, but nothing we did seemed to slow down the idle.

    So we gave up for the night and went out for a bite to eat and on the way back we stopped for gas. Almost instantly the idle started slowing down until it went back to normal! Weird!
  18. Pakrat

    Pakrat Founding Member

    Joined:
    Aug 6, 2000
    Messages:
    3,856
    Likes Received:
    0
    Trophy Points:
    56
    Good analagy. Diluting the problem just isn't the answer as there is no chlorine or refinement addative that will restore the gas to a useable or acceptable level like you could do with water. You could just run it out, but then you will certainly risk causing a performance problem elsewhere at some point that may not be as easy a fix. The second mistake was adding new gas to bad and you should just cut your losses and drain it. If you follow our reccomendations, you will likely stop running rough within 10 minutes time without hurting anything else.

    As for the drained gas, once you get it out and get a closer look at it, you may notice that the newer gas has seperated, and it could possibly be ladeled off from the top and reused in a mower or something so it isn't a total loss, but whatever you keep it in, be sure to stabalize it or it too will go bad before spring. If not, the GBM can give you all kinds of other uses for it as opposed to recycling. :rolleyes:
  19. KaPPaBaLL

    KaPPaBaLL New Member

    Joined:
    Nov 29, 2003
    Messages:
    1,328
    Likes Received:
    0
    Trophy Points:
    0
    no problems here.. because it's always summer in california :D
  20. colt65

    colt65 Founding Member

    Joined:
    May 31, 2002
    Messages:
    142
    Likes Received:
    0
    Trophy Points:
    0
    Ok, drained the tank entirely, refilled with 91 and put Gumout fuel cleaner in the tank. Everything is running better but not perfect... now I get to dig into the carbs and see if I need to rejet.

Share This Page