vacuum line? please tell me what this is?

Discussion in '96-04 - 2V Specific' started by GT3FC, Jan 21, 2014.

  1. GT3FC

    GT3FC Active Member

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    Alright so here's the deal I have a nice little vacuum leak causing my idle to jump aroune between 1k and 1300rpms. I recently broke this line (the red one):
    [​IMG]
    I broke this line by accidentally leaning on it and it snapped. while running i can feel that it is pulling vacuum from the plenum side. my major question is what is this line? it might be a stupid question but I just dont know the answer. also i re connected the broken ends together with a small length of vacuum hose and it still acts like there is that vacuum leak. Do you think that a vacuum hose holding it together would be able to hold vacuum? if not do you think some silicon would hold it together and hold vacuum until I get the extra time to replace the line?
    help please this is the one thing that is stopping my engine froom running perfectly and its bothering me!
     
  2. 96blak54

    96blak54 Legend

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    Do yourself a favor and replace the entire line with quality vac line. Do this to all lines to prevent any further problems from an old decreped ready to break brittle line. Any vac line on our cars leaky is a major kill switch.
     
  3. Ferocious

    Ferocious Legend SN95 Supporter

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    I believe that is the fuel injection vacuum line.
    part# 9E498

    [​IMG]
     
  4. rz5.0

    rz5.0 Legend

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    Ive used a small piece of vacuum hose with silicone as a temporary fix before. It worked just fine.
     
  5. redriderjf87

    redriderjf87 New Member

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    Ok, I admit I'm dense, I've been fighting a potential vacuum issue / rich bog condition ever since changing out my tb/plenum last summer. For some reason I never paid much attention to that red line(s). This will have me up all night now wondering, thanks OP :tongue:
     
  6. GT3FC

    GT3FC Active Member

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    haha that's what I'm here for.. Make sure not only to check that line but to also check the rubber fittings that the lines go into. when I replaced mine today I found out that one of the rubber fittings had a good sized hole that opens up when it flexes, so I patched it up with some silicon and I still have a leak somewhere that I cant find :mad:
     
  7. 96blak54

    96blak54 Legend

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    Keeping them vac lines and rubber fittings in check for the condition is as important as oil level to a performance enthusiasts. These modulars dont have many vac lines or rubber fitting but if their is um-metered air entering or exiting the engine, the computer does not know whats going on. This leads to a poor running conditions.

    I suggest anyone reading this to go poke under the hood for a minute. Check condition of the rubber, line flexability, and be sure the lines are covered with corrugated plastic wire loom. This will prevent the vac line from rubbing against something, rubbing out a hole.
     
  8. redriderjf87

    redriderjf87 New Member

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    Cool, will do. Thanks again. Was going to do an intro thread but got too excited when I saw this one lol.
     
  9. 97GT4.6

    97GT4.6 Active Member

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    I had one of these vacuum lines break, and it caused my HVAC blend door controls to be inoperative (default to defrost). Put on some new lines, and it fixed it. Nice to have an easy fix. But yeah, these things get very brittle after a while, and especially in the cold.
     
  10. redriderjf87

    redriderjf87 New Member

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    Well I guess mine looks solid, unfortunately. I was hoping for an easy fix, apparently I can't find any other vac leaks around the plenum with carb cleaner either. I will need to do some more searching and start a new thread for sure, apparently my email tunes are commanding 12.36 wot afr but the leanest I can get is 11-11.5 (per my wideband), and the bog is noticeable. Anyways thanks for the info, was still good to check those lines no doubt.
     
  11. GT3FC

    GT3FC Active Member

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    if your still having a vacuum leak be ure to check your EGR especially if you have an intake spacer or or nitrous plate. My vacuum leak was coming from my EGR valve
     
  12. redriderjf87

    redriderjf87 New Member

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    Thanks, I'll check that for sure. I remember taking one of the egr bolts was a pain in the butt for me since I didn't have a deep well socket at the time. Who knows, I hadn't really checked it for any leaks.