TBI Vacuum Hoses

Discussion in 'Tech Discussion' started by foamypirate, Aug 30, 2012.

  1. foamypirate

    foamypirate Full Access Member

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    Hey guys,
    I'm hooking up my vacuum lines on my TBI swap, and had a few questions. Figured since a few of you are TBI, you could probably help out.

    The first question I have is on the back of the intake manifold. There is a small silver Hex screwed into the manifold with a vacuum port and hose attached. What does the other end of that hose attach to?

    The other is cruise control related. In the cruise control harness, there is a large vacuum hose. Where does that attach to on the engine side? The interior side connects to the brake switch. I thought it connected to the cruise control servo, but it seems too large in diameter.

    The next one is on the MAP sensor. I have a vacuum line from the TB to the map sensor, but on the MAP sensor, there is port, but nothing hooked up to it. Should there be something hooked up there or is it open?

    The vacuum ball...where does its vacuum line attach?

    Last, but not least, the climate control harness coming out by the heater box has a vacuum hose, where does it attach to?

    I really wish I had taken more pictures when I tore down my 87, dangit! I looked through my factory manual, but couldn't find anything really.

    Thanks!
     
    Last edited: Aug 30, 2012
  2. RetroC10Sport

    RetroC10Sport Super Moderator Staff Member

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    There's two ports on the cruise servo, the larger one is for the large line and the smaller one is of course for the smaller hose getting engine vacuum.
     
  3. foamypirate

    foamypirate Full Access Member

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    Cool, thanks! It just seemed loose on there, so I wasn't sure.
     
  4. Jims86

    Jims86 Full Access Member

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    The HVAC hose goes to manifold vacuum, I T it in on my brake booster line.
    The MAP line comes from the back of the TB, the egr lin is from the passenger side port on the TB, PCV is the large port in the middle,EVAP is the medium port below the EGR.
    There should only be one vac port on your MAP.
     
    Last edited: Aug 30, 2012
  5. Jims86

    Jims86 Full Access Member

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    Yup, its teed into the climate control line.
     
  6. 89Suburban

    89Suburban Full Access Member

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    My manifold rear fitting has a hose coming out, then a check valve, then a T splitting off to the ac/heater and CC/vacuum ball.

    MAP sensor should have one line. Are you sure you are not referring to the EGR control valve? That has a vent port and 2 vacuum lines.
     
  7. 89Suburban

    89Suburban Full Access Member

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    And my brake vacuum line feeds off the front/right of the throttle body.
     
  8. foamypirate

    foamypirate Full Access Member

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    Thanks guys! That's exactly what I needed.

    89S, you are right, it was the EGR control valve. I was working from memory, and for some reason thought it was MAP.
     
  9. Jims86

    Jims86 Full Access Member

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    That would be funny as shit....hook up the map sensor wrong, start it, and he comes back posting that his 84 is rolling coal.
     
  10. 89Suburban

    89Suburban Full Access Member

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    Jims86 taught me. [​IMG]
     

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