Old gas?

Discussion in '96-04 - 2V Specific' started by 97stanger, Mar 6, 2016.

  1. 97stanger

    97stanger Legend

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    Well, I've been chasing down an issue I've had with my air fuel ratio for a little while now. The car seems to start, idle, and even cruise fine. All gauges and A/F ratio seem to be as expected for the car. When I go WOT, the car would go pig rich and seem to not have much power, rich as in 10.0 rich. My first gut instinct was that I had an issue with my meth not spraying, and the car was pulling timing which was making it go rich for safety purposes. I primed the meth pump, and everything seems to be spraying at the progressive controller setting that I have. I started talking to a buddy, asking me the last time I put fresh gas in the car. It's probably been a solid 6 months or so, due to the winters here in NJ. So next step I'm going to try to do is drain the gas (I only have about 1/4 tank left) and fill it with some fresh 93. Also going to check the plugs to see how these things look. Say that the issue is old gas...is there anything else I should be worried about, double checking? I've never used HEET, but should I maybe try to put a bottle of that in with this new fuel to try to get rid of any water moisture that might be in the tank? Any input/advice appreciated. Thanks
     
  2. RichV

    RichV Well-Known Member

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    6 months is not enough to cause drastic issues. My SVO has older gas in it than 6 months and it runs fine, under boost or normal driving. Water in the fuel can jack things up, but not sure about going pig rich due to that.

    But it should be an easy thing to get some fresh fuel, hows fuel pressure?
     
  3. 97stanger

    97stanger Legend

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    hmmm, I guess it isn't terribly long, but I figured it could potentially be the cause especially with my car being tuned on methanol. Like you said, it's worth it to try. I'm going to pull all the plugs and check them out too. Fuel pressure has had no change either
     
  4. Witzy0070

    Witzy0070 Active Member

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    Turn your boost setting really high so the meth won't kick on then take a drive under WOT and see what your AFR gauge says then.
     
  5. 97stanger

    97stanger Legend

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    I never thought of that, good advice. Luckily I have a sump tank so its very simple to drain this last 1/4 tank of gas and fill it up with some fresh 93. I'm going to do that first and going to pull the plugs to see how these things look. After that I'll crank up the boost setting for the meth really high and report back w/ AFR reading
     
  6. Witzy0070

    Witzy0070 Active Member

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    I am 10.0 on the AFR under WOT at 100% spray with dual nozzles.
     
  7. 97stanger

    97stanger Legend

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    Have you always been tuned that rich? Here is my last dyno session I had, looks like it should be around 11.5 - 12 or so at WOT through entire power band

    [​IMG]
     
  8. Witzy0070

    Witzy0070 Active Member

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    Only that rich with the meth. I don't mind it since I spray nitrous. However I wouldn't mind a better tune, but trying to tune for meth and nitrous gets a bit finicky. So I feel comfortable with the richness.
     
  9. 97stanger

    97stanger Legend

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    Are you running straight meth or 50/50? I have a very similar setup to yours, and soon to be nitrous as well and it seems like mine is way more lean than yours. What octane are you running? Do you do your own tuning?
     
  10. Witzy0070

    Witzy0070 Active Member

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    I run boost juice exclusively. So 50/50, the water percentage is good for cooling those IATs. I run 91, all I have access to around here. As far as tuning I am dyno tuned by Dan Hurigan on a handheld. Trying to hit 11.5 while spraying meth and nitrous at once is interesting. Plugs are cheap.
     
  11. 97stanger

    97stanger Legend

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    Same here, I only run boost juice as well. Maybe we are different because I'm running 93/meth compared to your 91.
     
  12. ttocs

    ttocs Legend

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    not sure I would say old gas at it takes a while for it to go bad but old-bad/dirty gas I could see. I learned long ago a tough lesson about NEVER fill up your gas tank if you see that the tanker truck is at the gas station filling it while you are there. They stir up any/all dirt sediment that has collected at the bottom of the tank and it get sucked up and put in your tank then if you fill it at the same time. I made this mistake one time and after replacing two fuel filters we finally had to pull the tank and replace the sock inside off it and it was brown/nasty. If your going to drain the tank it might be worth while to drop it and check inside or if you have a borescope take a look inside and see if it looks ok.
     
  13. 97stanger

    97stanger Legend

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    Thanks for the info. I just figured it could potentially be the cause of my issue, and is basically a free fix if it is. Luckily, I actually have a sump tank so I just have a nut on the bottom of the sump to drain it, so I won't even have to get involved with dropping the tank at all. Is there any truth to HEET, if I do have any condensation or water on the inside of this tank would this help pull that moisture out?
     
  14. ttocs

    ttocs Legend

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    not sure about heet but I know when I worked at intel we used alcohol to dry up the excess water that was in the chambers we cleaned. They had to be as dry as possible after the cleaning because of the extreme vacuum they were under. I would have assumed that if there was a better way that they would have had us using it.
     
  15. 97stanger

    97stanger Legend

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    Pulled the plugs today. Basically, cylinder #1 appears to have been burning extremely rich. #2, #3, #4, a tiny bit rich but not much. Entire passenger side, #5, #6, #7, and #8 appear to have been burning fine.

    Plug from passenger side how 5-8 are burning:

    [​IMG]

    Plug from #1:

    [​IMG]

    I'm also a little concerned about plug gap. The last time I even had a reason to change/inspect plug burning was when the car was dyno'd on meth, and my tuner changed plugs and gapped them himself. I just checked the gap on every plug and they are all .19 or so. From a quick search online, it seems like most guys are running in the .28-.30 range with spark plug gap and boost. Now keep in mind, I'm running 20psi, meth, and I was having spark blow out so now run a KB BAS so maybe thats the reason he went so tight? Any thoughts/opinions on this?
     
  16. Witzy0070

    Witzy0070 Active Member

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    Seems honestly too tight. I've seen other more aggressive set ups still in the .028 to .035 area. I am .032. Granted that's a lot of boost compared to my 13 psi. Widest gap without blowout, I'd suggest starting near .028. Messing with gap is easy to experiment with.
     
  17. g36 monkey

    g36 monkey Moderator Staff SN95 Supporter

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    I wish I was more knowledgeable on the subject. I am tuned in for an answer.
     
  18. 97stanger

    97stanger Legend

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    i think it's too tight too. I'm going to swing by a local tuner tomorrow and get his opinion. It's easy to experiment, just a PITA when running COP lol
     
  19. g36 monkey

    g36 monkey Moderator Staff SN95 Supporter

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    I would think with COP it would be easier :)
     
  20. vermilion

    vermilion Legend

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    i run a .025 gap on COP. im putting mine on stands in the next 2 weekends to fix a chaffed 02 wire. i honestly am not too happy yet with COP. i also could need new COPs. ive been worried more about getting the lightning running.