c3 & c4 corvette vacuum diagrams

Discussion in 'Engine: Repairs and Modifications & generally corv' started by grumpyvette, Jun 6, 2009.

  1. grumpyvette

    grumpyvette Administrator Staff Member

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    http://www.corvette-101.com/vacuum.htm
    http://garage.grumpysperformance.co...-rather-than-jumping-in-with-both-feet.14918/
    labeling connections

    viewtopic.php?f=50&t=6098

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    http://www.corvettefever.com/howto/53360/index.html
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    If you want confirmation for a certain year corvette then Chiltons repair manual, or a chevy shop manual
    usually has several diagrams for each year and configuration:


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    if you break a line or can,t find a line location, you should be easily able to fabricate a fully functional replacement line, if you want to buy a direct replacement call these guys

    http://www.ecklers.com/search.asp?actio ... chHistory=

    http://www.ecklers.com/search.asp?actio ... chHistory={CE049489-2F7F-4AC3-8519-6219AF833BE6}^^Keyword%3A+vacuum+line^^free_text+%3D+%22vacuum+line%22+%3B+

    related info
    http://www.mamotorworks.com/corvette?frame=3.3850

    http://www.vette2vette.com/

    http://www.google.com/imgres?imgurl=htt ... 2&ct=image

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    http://vetteworks.tripod.com/techdocuments/Vaccum.html

    http://www.docrebuild.com/dr-r-web/SPARK2.pdf
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    this may help some guys

    here are the diagrams if someone wants em :)


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    and vacuum lines up closer:
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    Last edited by a moderator: Nov 11, 2018
  2. grumpyvette

    grumpyvette Administrator Staff Member

    Re: c3 corvette vacuum diagrams
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    c4 corvettes
    link to sensor info you might need

    posting.php?mode=edit&f=80&p=1025

    http://chevythunder.com/fuel%20injectio ... 20DIAGRAMS
    1984
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    1985-91
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    1992-96

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    VACUUM LINE DIAGRAMS

    This page shows the most common vacuum line diagrams for stock TPI setups:

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    The diagram above is for 1985-1986 5.0L F-body (Camaro/Firebird) MAF TPI

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    1985 2.8L V6 MFI Camaro-Firebird Vacuum Line Diagram

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    1985 Corvette 5.7L TPI Vacuum Diagram

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    1986-89 2.8L V6 MFI Camaro-Firebird Vacuum Line Diagram

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    1986-1989 5.0 and 5.&L TPI Vacuum Line Diagram

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    1988-92 5.0L TBI Camaro-Firebird Vacuum Line Diagram. Manual trans

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    1988-92 5.0L TBI Camaro-Firebird Vacuum Line Diagram. Auto. trans

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    1990-91 Corvette 5.7L Vacuum Line Diagram

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    This diagram is for 1990-92 F-body (Camaro/Firebird) Speed density TPI

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    1990-92 3.1L V6 MFI Camaro-Firebird Vacuum Diagrams
     
    Last edited by a moderator: Apr 25, 2016
  3. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    Last edited: Apr 25, 2016
  4. NewbVetteGuy

    NewbVetteGuy Member

    OMG, I think you just saved me an insane amount of time!

    I just got my car back after getting headers installed and now it idles TERRIBLY and I can hear the dreaded vacuum leak hissing sound. They removed the SMOG pump as it's obviously not doing anything without the air recirculation ports in the stock manifolds, but I'm guessing that they didn't plug the vacuum line.

    The diagrams showing where the smog system's vacuum lines go with a stock QJet I think will come in VERY handy in tracking this down.


    Adam
     
  5. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

  6. chromebumpers

    chromebumpers solid fixture here in the forum Staff Member

    Hey Grumpy, thanks for the work you put out over gathering all the vacuum schematics. I was lucky that the owner before me took care of the headlight and wiper door system on my '71, they work to near perfection. Many don't know that there were Rolling production line changes to the 69,70 and 71 model yrs. for the vacuum system.
    The only thing that needs some attention now is the secret headlight washers that only ran in production until the beginning of the second half of 1971. Ira can have the fun that goes with sorting that out!
    Along with a dozen or so small features there are a few little known details not finishing the second half of 71s production and gone by the 72 model year. There is no where that I know of that lists all these items until you look at the NCRS Judging manual specifically written for 1970 - 1972 Stingrays.
     
  7. NewbVetteGuy

    NewbVetteGuy Member

    Can anyone explain to me why the heck there are so many different diameters of vacuum hose on our cars? Vacuum is vacuum; the diameter of the hose shouldn't change the amount of vacuum....
     
  8. chromebumpers

    chromebumpers solid fixture here in the forum Staff Member

    That's a great question.
    Think of an engine as a big air pump. During combustion the piston down stroke is pulling in air at a rate that is determined by the inlet source such as a throttlebody and it's opening size relative to the cylinder's capacity. You have the greatest amount of work for the engine to pull in air behind a closed throttle plate (high vacuum)(small hose). Opening the throttle plate (a large hose) and engine work (vacuum) is decreased as the air pressure differential becomes damped behind the throttle plate due to the abundant ambient air supply in front of the throttle plate.
    Different mechanical devises with actuation derived by vacuum may have different vacuum (and timing) needs. The greater the size hose, the lower the vacuum will be in a given amount of time. A small hose will provide a higher pressure over a shorter period of time.
    So different sizes and lengths in vacuum lines are needed for operational management. Keep in mind when purchasing rubber hose that it must be vacuum rated so that the hose does not collapse under high vacuum and each fitting and excess length creates friction as well as restrictions. Avoid the many ways lines get pinched.
    I really need to clean this up. I'll get a better explanation later when I can keep my eyes open. LOL!
     
    Last edited: Dec 20, 2016
  9. Resto-2

    Resto-2 Member

    SAE 30R7 Fuel Line is long lasting, high heat resistant and strong when used as emissions-vacuum-pcv routing of tubing/line/hose. It is not for any fuel injection system, even as a return line. Unrated tubing used for the windshield washer, headlights or light duty whatevers, will still serve as vacuum line, but fails early. http://www.gates.com/oreilly/tech_tips/PermeationResistantFuelLineHose.pdf
     
    Last edited: Dec 21, 2016

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