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69 Tbird no start/weak spark

Discussion in '1967 - 1988 Ford Thunderbird' started by Ghostman, Dec 19, 2017.

  1. Hello fellow Tbirds. Just bought a 69 Tbird from guy in Denver. Will not start getting plenty gas, checked to make sure timing is right(even removed vale cover to verify valves). Two questions. 1. how much voltage should I see at pos terminal of coil when key is on and when cranking. 2. I put a spark tester on three different plugs set at 10 kv. Got what seem to me a weak spark. move out to 20kv and no spark at all. This is a brand new coil(I put on), the previous owner said cap, rotor and wires are new. Any ideas why it is not starting and why spark is weak? Appreciate any info or ideas.
  2. captrick

    captrick Well-Known Member Lifetime Donor

    You might very well have a week coil. I replaced my coil with a Pertronics Flame thrower coil and it made a big diference. The stock coil only puts out about 28,000 volts the Pertronics puts out 40,000 volts. Check the voltage coming into the coil and make sure the points are making a good contact to ground. I think the points should be .oo28. Good luck Rick
  3. Hi ghostman I recently purchased a 67 with a 390 and also would not start had weak and erratic spark at the plugs put in a new coil and points and had the same result,did a little research and put on a new 7 dollar condenser under the dizzy and the old bird fired right up. Good luck let us know what you find.
    tbird likes this.
  4. Finally got it started. Put new condenser on it. Plus the shop the gentleman took it to in Denver had the timing way off and from them unsuccessfully trying to start it and me also. Oil was full of gas.
    tbird likes this.
  5. Glad you got it going!
  6. fordrodsteven

    fordrodsteven Well-Known Member Gold Donor

    Hope you changed the oil!
  7. fordrodsteven

    fordrodsteven Well-Known Member Gold Donor

    This is a copy of the tune-up specs from my Chilton's. The far right column (not visible) is RPM. The book says the idle RPM for a 1969 429 engine with automatic transmission is 550 RPM.
    Bird tune specs.jpg
  8. captrick

    captrick Well-Known Member Lifetime Donor

    That setting is with the engine at operating temperature and in gear. I would set the timing at 2500 rpm at 35 degrees with the vacuum line hooked up, if the engine knocks just back the timing off a degree or two at a time until the knock goes away. The reason for that is today’s gas is nothing like it was 50 ago.
  9. fordrodsteven

    fordrodsteven Well-Known Member Gold Donor

    I would say that you and I certainly have a difference of opinion. Oh well.
  10. Yes I did twice. Thanks for the info
  11. captrick

    captrick Well-Known Member Lifetime Donor

    I guess we do have a difference of opinion. I have a 1967 427 sideoiler with 2, 4 barrels and 11 to 1 pistons and I tune it at 2500 rpm and at 35 degrees. I run it on 93 octane pump gas and drive it every weekend and sometime even during the week. I also put in Petronics electronic ignition modular in the distributor to replace the points and condenser, I also added a flame thrower coil which puts out 48,000 volts to keep the plugs clean. I also reduced the amount of advance in the distributor so after I set the timing the initial timing is higher and the full advance doesn't exceed 35 degrees. These are old racing tricks from back in the day. It work fine for me and I don't have any problem.
  12. removed two metal back plates from my water pump.

    Would you happen to know a reason for two back plates to be on the water pump ?

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