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CTO switch

Discussion in 'Intermediate CJ-5/6/7/8' started by sdurkee, Jul 5, 2006.

  1. Jul 5, 2006
    sdurkee

    sdurkee SD

    Phoenix, AZ
    Joined:
    Jul 2, 2006
    Messages:
    24
    Hi,

    I had a question about the CTO or TVS as some people call them and it's hookup. I have had a problem passing emissions and this seems to be the culprit. I was unaware of the vacuum advance feature on the distributor and probably has been the main source of my timing woes over the years. Seems like in reading the manual that the most integral part of the system is the CTO. I am wondering if anyone has theirs hooked up? In my book it says it connects in 3 places. Distributor to the center port, outside port to the mainfold vacuum, and inside to a solenoid, then from the solenoid to the carb port. I am wondering if anyone has bypassed that solenoid and just run the CTO straight to the carb? Please let me know if you have, or if you have a functioning CTO or TVS as some people call them, thanks, Steve

    or for that matter any insight into the situation...thanks again
     
    sdurkee, Jul 5, 2006
    #1
  2. Jul 5, 2006
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
    Joined:
    Aug 10, 2003
    Messages:
    23,596
    Yes, I have one on my truck. It has no solenoid. It runs manifold vacuum when cold and ported vacuum when hot.

    The main difference between manifold and ported (carburetor) vacuum is the carburetor blocks off the vacuum port at idle. You need a little more advance when the engine is cold (for best drivability), so the distributor is connected to the vacuum all the time when cold. Once the engine warms up, ported vacuum is used which removes vacuum advance at idle.

    Look here: http://www.c104.net/manual/Section_04A.pdf

    The solenoid is only needed if your application has TCS. I thought we established yesterday that it does not?
     
    timgr, Jul 5, 2006
    #2
  3. Jul 5, 2006
    sdurkee

    sdurkee SD

    Phoenix, AZ
    Joined:
    Jul 2, 2006
    Messages:
    24
    I was unsure if it had it or not...that makes things much clearer. I do not know if it had it or not..I have what appears to be the solenoid switch on the tranny, but it may just be from an earlier restoration. The main thing I needed to know you answered though, about if I needed that solenoid or not. Thanks for the help, I found CTO at checker online, they are listed as a ported vacuum switch if anyone else is looking for a CTO here is the link for the '74/early '75

    http://www.partsamerica.com/ProductList.aspx?PartType=285&PTSet=A&SearchFor=Ported Vacuum Switch

    thanks for your help, much appreciated
     
    sdurkee, Jul 5, 2006
    #3
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