FYI FORD - MustangSteve's Ford Mustang Forum
The Internet's Most Knowledgeable Classic Mustang Information
IF YOU HAVE A QUESTION ABOUT CLASSIC FORD MUSTANGS, YOU HAVE COME TO THE RIGHT PLACE!
MustangSteve has over 30 years of Mustang experience, having owned 30 of them and restored several others. With the help of other Mustangers, this site is dedicated to helping anyone wanting to restore or modify their Mustang.... THERE ARE NO DUMB QUESTIONS!!!!!
Visit MustangSteve's web site to view some of my work and find details for:
FYIFORD Contributors' PICTURES - Power Brake Retrofit Kits for 65-66 Stangs - Classic Mustang FAQ's by MustangSteve - How to wire in a Duraspark Ignition - Mustang Ride Height Pictures and Descriptions - Steel Bushings to fit Granada Spindles to Mustang Tie Rods - Visit my EBAY store MustangSteve Performance - How to Install Granada Disc Brakes MustangSteve's Disc Brake Swap Page - FYIFORD Acronyms for guide to all the acronyms used on this page - FYIFORD Important information and upcoming events

You are not logged in. Would you like to login or register?

  • Index
  •  » FYI Ford, Classic Mustang Tech Discussion
  •  » Vacuum connections on the 66 EFI 5.0 HO

    • 1 of 1

       

    3/13/2023 1:38 PM  #1

    gkm24
    FYI Addict

    Offline

    From: Winchester, Hampshire, England
    Registered: 6/08/2013
    Posts: 108

    Vacuum connections on the 66 EFI 5.0 HO

    Finally connecting the exhaust and then will be running my new install.
    Can I confirm the Vacuum connections with anyone?
    I have a connection from the inlet manifold to the brake servo, the fuel pressure regulator and the pcv valve.
    There is a connection on the valve cover at the oil filler as well. If I have the pcv valve connected to the inlet manifold, do I need this one? 
    The last one is the MAP sensor.
    Is this all I need?

    Is there a preference to connect to the inlet manifold or the throttle body on any of these connections?
    The set up is a Mass Air system and not an SD.
    Thanks for your help and advice.

     

    3/13/2023 3:49 PM  #2

    TKOPerformance
    Hyper FYIFORD ADDICT

    Offline

    From: Newark, DE
    Registered: 12/15/2014
    Posts: 7,486

    Re: Vacuum connections on the 66 EFI 5.0 HO

    There is a nipple on the oil fill tube that connect to the throttle body.  There is a plastic hose with rubber ends on it for this on factory EFI Fox body cars. 

    The intake was used for the vacuum source for everything other than the line I noted first.  There is a steel vacuum tree that threads into the intake on the underside. 

    There are more connections on a factory installation, but this is what's necessary to run the engine.  There are TAB and TAD solenoids and valves that control the AIR pump which I doubt you are going to run. 
     

    Last edited by TKOPerformance (3/14/2023 4:08 PM)

     

    3/13/2023 5:02 PM  #3

    50vert
    Senior 24-7 FYI Addict

    Offline

    From: QLD Australia
    Registered: 4/01/2013
    Posts: 1,420

    Re: Vacuum connections on the 66 EFI 5.0 HO

    The line from the oil fill is needed so that the air for the PCV system is metered by the MAF meter, also need a line for the fuel pressure regulator.
    Edit: you've already covered the F/P regulator.

    Last edited by 50vert (3/13/2023 6:17 PM)

    "Those telephone poles were like a picket fence"
     

    3/13/2023 10:31 PM  #4

    Nos681
    Senior 24-7 FYI Addict

    Offline

    From: Atlantic Mine, Michigan
    Registered: 7/14/2016
    Posts: 3,326

    Re: Vacuum connections on the 66 EFI 5.0 HO

    MAP = Speed density and connects to manifold vacuum

    BAP = Mass air flow and NO connection to manifold at all.

    BAP sensors have a plastic snap on collar to prevent a vacuum line to be installed.


    Last spring I was testing a SD ECM and forgot to connect to manifold vacuum.
    It wouldn’t run at idle, higher rpms like +2k was kinda okay.
    When I went inside to warm up, it dawned on me that I forgot the vacuum line.

    Please note,.. I was able to do this because of my deleted TAB and TAD solenoids.
    Before I forget, MAF had to be disconnected to test SD ECM. Only 2 changes for me to switch ECM’s.

    If you’re running an EGR valve, you’ll need a vacuum line to the EVR.

    Last edited by Nos681 (3/13/2023 11:21 PM)

     

    3/14/2023 8:19 AM  #5

    Raymond_B
    Senior 24-7 FYI Addict

    Offline

    From: Fort Worth, TX
    Registered: 4/01/2013
    Posts: 1,199

    Re: Vacuum connections on the 66 EFI 5.0 HO

    Hmmm as I understand it the sensor in question is used differently depending on MAF or SD. SD uses a MAP sensor and MAF uses a BAP sensor. MAP sensor = vacuum line connected, BAP sensor = vacuum line *disconnected*. Manifold vacuum vs barometric pressure.

     

    3/14/2023 9:50 AM  #6

    gkm24
    FYI Addict

    Offline

    From: Winchester, Hampshire, England
    Registered: 6/08/2013
    Posts: 108

    Re: Vacuum connections on the 66 EFI 5.0 HO

    Thank you for your help. All noted and connections made accordingly. The Bap sensor does have a collar on it and will not be connected to the manifold. I am not running an air pump on the vehicle.

       •Thread Starter
     

    3/14/2023 10:27 AM  #7

    Bullet Bob
    Senior 24-7 FYI Addict

    Offline

    From: Montrose, Colorado
    Registered: 4/01/2013
    Posts: 4,885

    Re: Vacuum connections on the 66 EFI 5.0 HO

    What Dan said....MAP & BAP are the same sensor.  Manifold Absolute Pressure get the vacuum line.  Barometric Pressure DOES NOT get manifold vacuum.  And if you run EGR the EGR position sensor on the upper intake AND the EGR vacuum control solenoid will need manifold vacuum.
    Also, as Barry says....he's seldom if ever wrong...fresh, clean and metered air for the PCV come from the elbow directly in front of the throttle butterfly on the TB. 
    And also, if you run a canister you will need vacuum to the Canister Purge Solenoid Valve, then to the canister.
    NOTE:  If you do not run a canister/canister purge you will need to install a vent to atmosphere on the 65/66 fuel tank.  Otherwise the hot fuel returning will cause the tank to resemble a beach ball.  Don't ask how I know this.  I installed a vent line high in the filler neck and ran that to my canister.  Works well.
     

    "you get what you pay for, good work isn't cheap, and there are NO free lunches...PERIOD!"
     

    3/14/2023 11:24 AM  #8

    gkm24
    FYI Addict

    Offline

    From: Winchester, Hampshire, England
    Registered: 6/08/2013
    Posts: 108

    Re: Vacuum connections on the 66 EFI 5.0 HO

    Thank you everyone that has helped me with this conversion.
    Started on the button, runs beautifully and sounds great. I haven't put any water in it yet as I still have to fit out the interior but definitely spurred on by the success so far.

       •Thread Starter
     

    3/14/2023 4:19 PM  #9

    50vert
    Senior 24-7 FYI Addict

    Offline

    From: QLD Australia
    Registered: 4/01/2013
    Posts: 1,420

    Re: Vacuum connections on the 66 EFI 5.0 HO

    gkm24 wrote:

    Thank you everyone that has helped me with this conversion.
    Started on the button, runs beautifully and sounds great. I haven't put any water in it yet as I still have to fit out the interior but definitely spurred on by the success so far.

    Congrats, first run is a big milestone. Now all you need is a bridge across the pond. Or fly in to the Bash .... if you can swing it ... you'll be glad you did.
     

    "Those telephone poles were like a picket fence"
     

     

    1 of 1

  • Index
  •  » FYI Ford, Classic Mustang Tech Discussion
  •  »  Vacuum connections on the 66 EFI 5.0 HO

    • Board footera


    REMEMBER!!! When posting a question about your Mustang or other Ford on this forum, BE SURE to tell us what it is, what year, engine, etc so we have enough information to go on.