Announcement

Collapse
No announcement yet.

74 Triumph TR6 Starting challenge

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • 74 Triumph TR6 Starting challenge

    Hi all....I have kind of strange problem I have been chasing for a couple years and want to get it fixed.....When I turn the ignition to on the green alternator light comes on however when I turn the ignition to start, the engine turns over and the green light goes out.... I can hold the key with engine turning over until the cows come home but it will never - ever start. It is only when I release the key from start back to ignition on does the car suddenly catch and start up.....

    Can be quite frustrating at times...? Cleaned all the contacts at the alternator to no avail, thinking it could be the ignition switch????


    Thanks
    Randy

  • #2
    Originally posted by SeaHag View Post
    Hi all....I have kind of strange problem I have been chasing for a couple years and want to get it fixed.....When I turn the ignition to on the green alternator light comes on however when I turn the ignition to start, the engine turns over and the green light goes out.... I can hold the key with engine turning over until the cows come home but it will never - ever start. It is only when I release the key from start back to ignition on does the car suddenly catch and start up.....

    Can be quite frustrating at times...? Cleaned all the contacts at the alternator to no avail, thinking it could be the ignition switch????


    Thanks
    Randy
    Randy --- Just as a test, run a separate jumper wire from the "green" fuse to the + side of the coil. Let's see if having a direct hot contact to the coil when the key is turned to 'start' allows the engine to fire. If it does, could be that the 12V wire from the starter to the coil isn't making contact (but it will start with the lesser voltage.) Assuming you have two wires there now.

    Dick

    Comment


    • SeaHag
      SeaHag commented
      Editing a comment
      Not familiar with the green fuse. All mine have long since been replaced with the glass jobs. How many down from the top is it?

    • poolboy
      poolboy commented
      Editing a comment
      He means the fuse that's protecting the green wires....normally there would be a white wire, the fuse, then the green wires.

  • #3
    Check, clean and check the charge level of the battery. Ive had weak batteries that the cranking took just enough juice away to fire.
    '74 TR6 CF13007U aka "Mr. T"
    Custom Blue (Delft-Like) and New Tan (Formerly Mallard and New Tan)
    Points, Ballast Bypassed, Bosch Blue Coil, Moss Cobalt Wires, Champion RN12YC plugs.
    Peaks and tweaks, but the spirit of Original
    Redlines always.
    My wife is the Driver, I'm just the Mechanic....

    Comment


    • #4
      Maybe check your ignition ballast setup. 12v at coil in start position, and 6v during run for a 74 methinks...
      1974 TR-6 Logic Overdrive

      Comment


      • Derekmcallister
        Derekmcallister commented
        Editing a comment
        That's correct for a '74 if the ballast is still in use. Many have converted to non-ballast coils and bypassed the resistor wire (like me).

    • #5
      Quick update on troubleshooting, seeing strange stuff.

      Without key I am getting .3 V on the positive side of the coil
      without key I am getting .2 V at the Green wire of the fuse box
      Turning ignition on, one light comes on the red ignition light

      I get 11.4 V at the green wire on the fuse box
      I get 8.2 V on the positive side of the coil

      attempting to start

      the positive side of the coil drops to 1 volt.
      When I release the key back to ignition, the voltage is 12.3 V on the positive side of the coil.
      Attempt to restart and again the voltage drops to 1V.
      Ignition to off position and voltage is .3 V.

      Any my ideas where to start looking ?

      i have a new ignition switch but I’m reluctant to open thatcan of worms unless I have to.

      Comment


      • #6
        What is the voltage of the battery? Do you have a load tester for it?
        '74 TR6 CF13007U aka "Mr. T"
        Custom Blue (Delft-Like) and New Tan (Formerly Mallard and New Tan)
        Points, Ballast Bypassed, Bosch Blue Coil, Moss Cobalt Wires, Champion RN12YC plugs.
        Peaks and tweaks, but the spirit of Original
        Redlines always.
        My wife is the Driver, I'm just the Mechanic....

        Comment


        • SeaHag
          SeaHag commented
          Editing a comment
          No load tester but it measures about 12.8 V

      • #7
        In regard to your .3 & .2V readings check to see that your oil pressure switch is wired as per this diagram.

        Oil Pressure Switch diagram

        In regard to the starting problem, did you do the test Dicta suggested? if so, what happened?

        Are there two wires on the positive terminal of the coil, a white/yellow and another that you might not be able to determine the color?

        R3
        Jim Herter Copperas Cove, TX
        Original Owner ֍ 1970 TR6 ֎ CC 50990 LO
        VDU 506H

        Comment


        • SeaHag
          SeaHag commented
          Editing a comment
          Checked the wiring to the oil pressure sensor and all appears correct.

      • #8
        I also swapped the points out for electronic ignition several years back and has been working great.

        Comment


        • #9
          Battery voltage appears good, but there are two unanswered questions on the table....
          '74 TR6 CF13007U aka "Mr. T"
          Custom Blue (Delft-Like) and New Tan (Formerly Mallard and New Tan)
          Points, Ballast Bypassed, Bosch Blue Coil, Moss Cobalt Wires, Champion RN12YC plugs.
          Peaks and tweaks, but the spirit of Original
          Redlines always.
          My wife is the Driver, I'm just the Mechanic....

          Comment


          • #10
            What about the starter relay wiring and condition of these connections? Check your setup against the 74 wiring diagram. See if you have both ballasted (run) and starting (full 12v) wires at the coil positive terminal?
            Last edited by Mike K; 08-15-2019, 06:17 PM.
            1974 TR-6 Logic Overdrive

            Comment

            74 Triumph TR6 Starting challenge

            Collapse

            Search

            Collapse

            There are no results that meet this criteria.

            6-Pack Statistics

            Collapse

            Topics: 38,369   Posts: 478,208   Members: 8,236   Active Members: 256
            Welcome to our newest member, jeremygarofalo.

            Upcoming Events

            Collapse

            Working...
            X