Close



Results 1 to 13 of 13
  1. #1
    FEP Member Tyrel's Avatar
    Join Date
    Nov 2013
    Location
    Chilliwack B.C.
    Posts
    161

    Default question about egr selenoid and tab and tad sensor vacuum lines

    So I want to make sure I have all the vacuum lines right on my car from the above sensors.

    Egr selenoid top vacuum line goes to the egr valve, but where does the bottom one go to? Intake manifold?

    Tab and Tad selenoid I know one or two of them go to the smog pump things but I'm not exactly sure on the routing and dont understand the diagrams. I know they both have two vacuum lines but if someone could provide me with a detailed description of which ones are supply and where the supply comes from and which ones go to the emissions equipment, i would greatly appreciate it. I hate guess work lol.

    And which one is the tab selenoid and which one is the tad selenoid. Better be sure on that one too.


    Anyways, thanks for any and all help.

  2. #2
    FEP Senior Member rob342's Avatar
    Join Date
    Aug 2014
    Location
    darien, il
    Posts
    522

    Default

    i'm writing this how i'm writing this, based on your other thread about deleting all this stuff.
    --

    tab/tad can both be disconnected. vacuum lines plugged, electrical connectors off. if you disconnect one, disconnect BOTH. i plugged the vacuum lines right at the solenoids. if you plug them too close to the motor, you will end up blocking vacuum from reaching other things, such as the HVAC controls.

    if you do this, you NEED to block off the 1" line running from the smog pump to the exhaust pipes. if you do not do this and the smog pump pumps air into the exhaust, your o2 sensors will detect the oxygenated air and it can cause your car to detect a false lean condition. this will throw false lean codes, causing the car to run rich(trying to compensate for it thinking it's lean). i just went through this and it was a NIGHTMARE to figure out. in my case it was all caused by a cracked TAD solenoid. since disconnecting them, my car runs great.


    --
    if you disconnect the EGR lines, you need to disconnect the EGR electrical plug as well. if you do not, the car will add timing, see table below.. i only warn you about this because some people leave the egr solenoid plugged in to avoid a the MIL light on the dash. the proper way to do it is to use a resistor in the EGR connector. with the resistor the car will not bump the timing and the light will stay off.

    personally, on my car i chose to remove the smog, but leave the EGR active. it only injects a small amount. it injects up to 11% EGR maximum. it's only active from 900rpm to 2500rpm and only when the motor is at 50% load or less. EGR has no effect on WOT performance, it helps cool the chambers, helps reduce emissions, and helps slightly with fuel economy.

    this is an a9l EGR table(plagiarized from sbftech):


    unless you're upgrading to non-egr heads or a non-egr intake, there is really no reason to remove it unless you want slightly worse economy and more pollution.

    when you remove the TAB/TAD solenoids, leave the wiring intact. the red wires can be used as key on power for your future projects. i have the red wire from my TAD connector wired to the ignition+ wire for my electric fan controllers.

    i just went through all this and i was helped greatly by the experts on sbftech.com if you delete the EGR and need to know which resistor to use in the connector, you can find info like that over there.
    Last edited by rob342; 08-21-2014 at 06:52 PM.

  3. #3
    FEP Member Tyrel's Avatar
    Join Date
    Nov 2013
    Location
    Chilliwack B.C.
    Posts
    161

    Default

    I have already taken out the smog pump hoses and plugged the lines to the exhaust and the cylinder heads. Do I absolutely have to unhook the electrical connectors to the tab and tad selenoid? And I plan on keeping the egr. Juat need to figure out where the supply line comes from. Im guessing it comes from under the intake manifold. Please correct me if I'm wrong.

    And the routing of the vacuum lines for the tab and tad sensors. I know there is that one line that splits into two that has the one way check valve in it. What is that for? And where is it supposed to come from and go?

  4. #4
    FEP Senior Member rob342's Avatar
    Join Date
    Aug 2014
    Location
    darien, il
    Posts
    522

    Default

    if you unplug the solenoids, the car throws codes that do not effect operation in any way. they will not turn on the check engine light, the codes just tell you those are not present. you should definitely unplug them.

    just an FYI.. if you still have catalytic converters on the car you should remove those too. the smog pump is what prevents them from clogging

  5. #5
    FEP Senior Member rob342's Avatar
    Join Date
    Aug 2014
    Location
    darien, il
    Posts
    522

    Default

    the EGR supply comes from the thermactor holes in the exhaust ports. it runs through the heads, through the lower intake, through the upper intake, into the throttle body spacer, through the egr valve, and into the intake plenum.

    *you're thinking too hard. it comes from the little hole in the middle of the 8 intake ports



    i was confusing myself with that too.
    Last edited by rob342; 08-21-2014 at 07:27 PM.

  6. #6

    Default

    Quote Originally Posted by rob342 View Post
    the EGR supply comes from the thermactor holes in the exhaust ports.
    Umm.... no. EGR comes from the crossover passages in the cylinder heads, if so equipped, whether
    or not those cylinder heads also have thermactor passages. Thermactor and EGR are two completely
    separate systems.
    Cheers,
    Jeff Cook

    '85 GT Hatch, 5-speed T-Top, Eibachs, Konis, & ARE 5-Spokes ... '85 GT Vert, CFI/AOD, all factory...
    '79 Fairmont StaWag, 5.0, 62K original miles ... '04 Azure Blue 40th Anny Mach 1, 37K original miles...
    2012 F150 S-Crew 4x4 5.0 "Blue Coyote"... 65 coupe, 289 auto, Pony interior ... '67 coupe 6-cyl 4-speed ...
    '68 Vert, Mexican block 307 4-speed... '71 Datsun 510 ...
    And a 1-of-328 Deep Blue Pearl 2003 Marauder 4.6 DOHC, J-Mod, 4.10s and Lidio tune

  7. #7
    FEP Senior Member rob342's Avatar
    Join Date
    Aug 2014
    Location
    darien, il
    Posts
    522

    Default

    Quote Originally Posted by JACook View Post
    Umm.... no. EGR comes from the crossover passages in the cylinder heads, if so equipped, whether
    or not those cylinder heads also have thermactor passages. Thermactor and EGR are two completely
    separate systems.
    yea intake face of the head goes to a small opening in the roof of the third exhaust port from the front when looking at a head with the intakes facing left. sorry i was just trying to answer his question without being overly confusing. next time i'll focus on pleasing experts like you instead.

  8. #8
    FEP Senior Member rob342's Avatar
    Join Date
    Aug 2014
    Location
    darien, il
    Posts
    522

    Default

    I just wanted to come back on and apologize. I really like this place and don't want to wear out my welcome. Sorry Jacook. I apologize for my kinda snotty reply. (:

  9. #9
    FEP Member Mgino757's Avatar
    Join Date
    Jan 2011
    Location
    Virginia Beach, VA
    Posts
    489

    Default

    Does anyone know which vacuum resistor or restrictor goes on the top vacuum hose coming from the TAD solenoid on my 85 GT 4bbl?
    1985 Mustang GT conv. modified 4180C, Weiand Street Warrior intake, equal length headers, true dual exhaust, 3.55:1 8.8'' rear end, 2003 V6 T5, Ford Racing 10.5" clutch.

    1998 Mustang GT auto. PI swapped. Daily beater

  10. #10

    Default

    Quote Originally Posted by Mgino757 View Post
    Does anyone know which vacuum resistor or restrictor goes on the top vacuum hose coming from the TAD solenoid on my 85 GT 4bbl?
    There shouldn't be one. The line from the top of the TAD solenoids goes through a combination of L, T, and Y
    fittings on it's way to the EGR thermal vacuum switch, but it's otherwise a straight-through deal.

    Apart from the evaporative system, the only other restrictor on the '85 4V HO engine is in the manifold vacuum
    feed to the ignition advance thermal vacuum switch (the one with the electrical connector).
    Cheers,
    Jeff Cook

    '85 GT Hatch, 5-speed T-Top, Eibachs, Konis, & ARE 5-Spokes ... '85 GT Vert, CFI/AOD, all factory...
    '79 Fairmont StaWag, 5.0, 62K original miles ... '04 Azure Blue 40th Anny Mach 1, 37K original miles...
    2012 F150 S-Crew 4x4 5.0 "Blue Coyote"... 65 coupe, 289 auto, Pony interior ... '67 coupe 6-cyl 4-speed ...
    '68 Vert, Mexican block 307 4-speed... '71 Datsun 510 ...
    And a 1-of-328 Deep Blue Pearl 2003 Marauder 4.6 DOHC, J-Mod, 4.10s and Lidio tune

  11. #11
    FEP Member Mgino757's Avatar
    Join Date
    Jan 2011
    Location
    Virginia Beach, VA
    Posts
    489

    Default

    Mine must have a different configuration. Any idea what color the vacuum resistor would be on the manifold vacuum feed to the PVS for the distributor?

    Name:  20170325_224228.jpg
Views: 936
Size:  108.0 KB
    1985 Mustang GT conv. modified 4180C, Weiand Street Warrior intake, equal length headers, true dual exhaust, 3.55:1 8.8'' rear end, 2003 V6 T5, Ford Racing 10.5" clutch.

    1998 Mustang GT auto. PI swapped. Daily beater

  12. #12

    Default

    Quote Originally Posted by Mgino757 View Post
    Any idea what color the vacuum resistor would be on the manifold vacuum feed to the PVS for the distributor?
    Mine is green.
    Cheers,
    Jeff Cook

    '85 GT Hatch, 5-speed T-Top, Eibachs, Konis, & ARE 5-Spokes ... '85 GT Vert, CFI/AOD, all factory...
    '79 Fairmont StaWag, 5.0, 62K original miles ... '04 Azure Blue 40th Anny Mach 1, 37K original miles...
    2012 F150 S-Crew 4x4 5.0 "Blue Coyote"... 65 coupe, 289 auto, Pony interior ... '67 coupe 6-cyl 4-speed ...
    '68 Vert, Mexican block 307 4-speed... '71 Datsun 510 ...
    And a 1-of-328 Deep Blue Pearl 2003 Marauder 4.6 DOHC, J-Mod, 4.10s and Lidio tune

  13. #13
    FEP Member Mgino757's Avatar
    Join Date
    Jan 2011
    Location
    Virginia Beach, VA
    Posts
    489

    Default

    Awesome, thanks!

    Would a red restrictor be a suitable substitute?
    Last edited by Mgino757; 03-25-2017 at 11:38 PM.
    1985 Mustang GT conv. modified 4180C, Weiand Street Warrior intake, equal length headers, true dual exhaust, 3.55:1 8.8'' rear end, 2003 V6 T5, Ford Racing 10.5" clutch.

    1998 Mustang GT auto. PI swapped. Daily beater

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •