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  • This should be a simple problem but......

    Long post warning.
    Newbie to the 60degree world here. New to the engine but have been building cars for 30+ years, this one has me banging my head into a wall.
    I have a 1995 3.4L (L32) engine from a Camaro with a WC T5 behind it. The engine is currently in in a 1970 Triumph Spitfire. (it's a bad idea on wheels)
    The fuel injection system has been replaced with a custom intake and a Holley 390CFM 4bbl.
    The distributor is a vacuum advance unit from an 84 S10.
    It is using a single canister coil with an external voltage resistor stepping it down to about 11V DC

    NEW: wiring (complete car, tip to tail, no old wire at all), plug wires, plugs, distributor wires (internal distributor to coil), coil, distributor (complete unit), rotor, cap.

    THE PROBLEM: Cold, the car starts and runs beautiful, it purrs. Then it shuts down like the key was turned off and there is no spark. Let it sit for a while (30 min to an hour) and it fires right off again and runs until lit doesn't.
    I have had a meter on the coil when it quits, and the coil had no interruption in voltage, although the voltage seemed high (14V) at the coil while running. thought I should remove the alt. from the equation....

    Tonight, I disconnected the alternator, hooked it up to a 2 amp charge at the battery and started the car. voltage at the coil was 11V DC (running through the resistor), It purred along for 09:59 then quit. No spark. I changed the coil for another unit and started it up, again it purred along and then dies at 9:59. no spark. constant voltage to the coil. (yes, both times it ran for nine-minutes-fifty-nine-seconds, to the second) all the gauges: amp, temp, oil are all in the green. It runs beautifully until suddenly it doesn't.

    WTF?!?!?

    I have a coil pack (square, non-oil filled) for an 84 2.8L coming in the mail but I'm at my wits end here, it doesn't make any sense. Any advice aside from sacrificing a goat to the 60-degree gods?

    Thanks- Ryan
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  • Answer selected by SappySE107 at 03-16-2022, 03:08 PM.

    SOLVED IT! Ignition control module that came in the new distributor was bad out-of-the-box. Tested it by hooking a test light up to a hot wire and touching it to the negative coil tower while cranking - the ICM should send a trigger pulse that grounds the coil, which would flash the light. It didn't, then it did, then it kinda did, then it didn't. Changed the module and so far so good, the old 3.4 seems to be running strong. Brad, thanks for the discussion.

    Comment


    • #2
      I haven't missed with a car with a distributor for almost 30 years, so I'm not even sure where to start. But the time to shutdown being exactly the same is an interesting point. Could there be some type of fusible link or thermistor deal that may be a possible point of failure? It seems like it has to be something that resets, but with minimal knowledge of distributor systems, I can't really provide much help. Maybe I'll see if googling will come up with something helpful...
      -Brad-
      89 Mustang : Future 60V6 Power
      sigpic
      Follow the build -> http://www.3x00swap.com/index.php?page=mustang-blog

      Comment


      • #3
        I don't mess with carbs but I would think its either something getting hot and expanding or as Brad said, its a fusible link. Not much else to the car since there isn't a computer. What happens if the coil sees 14v? That is typical voltage for a running engine.
        Ben
        60DegreeV6.com
        WOT-Tech.com

        Comment


        • #4
          Does your distributor have a module inside it, for like electronic ignition? I have seen those go bad. By what you are describing as your setup, it sounds like you don't, but not sure.
          -Brad-
          89 Mustang : Future 60V6 Power
          sigpic
          Follow the build -> http://www.3x00swap.com/index.php?page=mustang-blog

          Comment


          • #5
            Thanks for the replies, and I agree with everything that's been said - something has to be heating up, but I can't figure out what. No to the fusible links, I know every piece of wire in the car. Brad the distributor is a 1984 S10 vacuum advance unit (new from the box). It's a 2 wire magnetic pickup (+ and - from the coil posts). I started it up the other morning than it ran for 20 minutes, I turned it off with the key and it wouldn't restart... lost spark after that, there was power to coil, but no spark. Let it sit a while and it fired right off. Like the title says, this SHOULD be a simple problem, but it's got me baffled. A little history to the car - according to the P.O: "I was driving it, the coil went bad, I parked it and then got too fat to sit in it...." so there is a history of coil problems. Since then, everything was rewired and all the ignition components have been replaced. I'm still waiting on the coil pack and hoping it has something to do with using a canister coil.

            Comment


            • #6
              When you say all of the ignition components have been replaced, I would assume that would include the plugs. What about the distributor cap itscapelf?
              -Brad-
              89 Mustang : Future 60V6 Power
              sigpic
              Follow the build -> http://www.3x00swap.com/index.php?page=mustang-blog

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              • #7
                Everything has been replaced, plugs, wires, cap, pickup, distributor, coil, and all the wire to those components. After I finished wiring the car I started it with the old distributor, cap, wires, plugs and a different coil. It ran for 5-10 minutes then quit and lost spark. plus the coil got hot to the touch, buldged in fact. Everything has been changed since then but the problem persists minus the hot coil. I've also run the coil + straight from the battery to bypass the harness and rule that out. Same result.

                Comment


                • #8
                  SOLVED IT! Ignition control module that came in the new distributor was bad out-of-the-box. Tested it by hooking a test light up to a hot wire and touching it to the negative coil tower while cranking - the ICM should send a trigger pulse that grounds the coil, which would flash the light. It didn't, then it did, then it kinda did, then it didn't. Changed the module and so far so good, the old 3.4 seems to be running strong. Brad, thanks for the discussion.

                  Comment


                  • #9
                    So it did have a module in it. Well good to know and glad you got it figured out! I seem to remember when I had my issue way back when, it took changing out that module like 3 times before it was finally fixed.
                    -Brad-
                    89 Mustang : Future 60V6 Power
                    sigpic
                    Follow the build -> http://www.3x00swap.com/index.php?page=mustang-blog

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