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Technical Engine shut down at 60mph cruising

Discussion in 'Traditional Hot Rods' started by ace high, Aug 27, 2017.

  1. ace high
    Joined: Dec 15, 2007
    Posts: 210

    ace high

    Looking for diagnostic opinions. Hemi 331. 3 deuce 97s, new tank, carter electric fuel pump, MSD distributor with magnetic pickup, MSD 6AL contol unit. Just recently, cruising at 60, engine starts to balk and finally shuts down. Wait 5 to 10 minutes, then starts right up and then repeats sgain. (Driving me "=÷%×+ crazy.
    Last edited: Aug 27, 2017
  2. squirrel
    Joined: Sep 23, 2004
    Posts: 46,708


    I would probably check for spark as soon as possible after it dies. My spark checking tool is a spark plug with the ground electrode cut off, and a big clip lead clipped to the threads, and I clip the other end of the lead to ground. Put the plug into one of the plug wires, and crank the engine, see if it gets a spark. The idea with the ground electrode cut off, is that it takes a strong spark to jump the larger gap, so if it will fire the modified plug, it will fire the normal plugs in the engine, under compression conditions.

    If no spark, it's an electric/electronic problem. If you get spark, then see if there is fuel in the carbs. If you have progressive linkage, then it should only run the center carb out of fuel...???? but if it's straight linkage, who knows what will happen..
    funk 49 likes this.
  3. chriseakin
    Joined: Jan 21, 2009
    Posts: 336


    Check your coil to make sure it's in good condition and make sure your fuel line isn't getting too hot. My sister had a similar experience and the coil was shorting between one of the connectors and the coil post due to a crack in the main wire nipple (or whatever it's called).
    dan31 likes this.
  4. BJR
    Joined: Mar 11, 2005
    Posts: 6,457


    Have you changed your gas cap recently? If you went from a vented one to a non vented one, or the vent is plugged you will run out of gas until enough air gets back into the tank to let the gas flow, then it will start again.
    tb33anda3rd and Special Ed like this.

  5. We have to isolate fuel/electrical issues first........
    Dan Timberlake likes this.
  6. lippy
    Joined: Sep 27, 2006
    Posts: 4,852

    from Ks

    Is this the same one with the oil pressure problem? Lippy
  7. Engine man
    Joined: Jan 30, 2011
    Posts: 3,476

    Engine man
    from Wisconsin

    Does it have an oil pressure switch on the fuel pump?
  8. ace high
    Joined: Dec 15, 2007
    Posts: 210

    ace high

    Yes it is
  9. blowby
    Joined: Dec 27, 2012
    Posts: 6,792

    from Nicasio Ca

    when my HEI module started dying out I put my inductive timing light on it, under the window wiper. When the engine would die, the light stopped blinking before the engine quit rotating so I knew it was spark. 5 minutes later it would run again.
    Dan Timberlake likes this.
  10. Kerrynzl
    Joined: Jun 20, 2010
    Posts: 2,284


    I had that issue, but usually the tank diaphragm's inwards, and siphons back overnight.
    [requiring gas being tipped down the carb to start it in the morning]

    In this case I would zip tie another coil to the car and test run it first.
    Usually a faulty module will flicker a tach needle
  11. ace high
    Joined: Dec 15, 2007
    Posts: 210

    ace high

    My first thought was fuel, whereas it starts back up after stopping for a few minutes. I figured electrical problem would last longer till things really cooled down.
  12. Johnboy34
    Joined: Jul 12, 2011
    Posts: 1,251

    from Seattle,Wa

    It's only a guess until you test and eliminate things.
  13. missysdad1
    Joined: Dec 9, 2008
    Posts: 2,942


    It's the coil telling you it's about to go on vacation. Been there, done that.
    olscrounger and X38 like this.
  14. old man hal
    Joined: Jun 21, 2017
    Posts: 92

    old man hal

    Misstsdad1 is right. I had the same problem and it was the coil.

    Sent from my iPad using H.A.M.B.
  15. Sheep Dip
    Joined: Dec 29, 2010
    Posts: 1,572

    Sheep Dip
    from Central Ca

    I had the same problem years ago on my 49 Chevy pickup dyeing for no apparent reason, I determined it was electrical, specifically the 12 volts to the HEI. I had power from ignition to the fuse block in the firewall, but nothing out to the HEI, for some reason continuity was being lost. I bypassed and ran a direct wire from ignition to HEI and it has never failed since.
    This is a Ron Francis harness, not brand X, every other circuit has performed flawlessly.
    Every car I have wired since regardless of brand or make of the harness gets a dedicated ignition wire bypassing the fuse block.
  16. classiccarjack
    Joined: Jun 30, 2009
    Posts: 1,440


    Believe it or not, I had a strange similar condition. After chasing my tail, I finally gave up and installed a new ignition switch.... It fixed the issue. To this day, I am still baffled.

    Sent from my XT1585 using The H.A.M.B. mobile app
  17. Must be bad juju, as I just started having the same problem.:mad:. Never before in 30 years of driving it.
    Random shutoff, no warning, burp, stumble, or fart.
    Pull over (pretty exciting in traffic) and it starts right up, and off we go.
    Mallory square coil, Holley red pump, 30 year old ignition switch.
    Guess I'll start changing out suspected culprits with my spares. I'm suspecting the Holley.
    Wish that I had some suggestions for you.
  18. I had a similar problem with the 351W in my '51 Ford F1. It turned out that one of the 3 wires in the distributor (Duraspark II) had gotten hooked by the vacuum advance linkage. When you hit a high vacuum situation, like cruising, it would pull on that wire just enough to ground it out and kill the ignition.

    Good luck, problems like these can be extremely frustrating.
  19. classiccarjack
    Joined: Jun 30, 2009
    Posts: 1,440


  20. ace high
    Joined: Dec 15, 2007
    Posts: 210

    ace high

    My first focus was trying to isolate a possible fuel issue. I took off the air inlet hose on the fuel tank and made sure it was totally clear. Electric Carter fuel pump seems to be functioning OK with enough delivery. Then I took the tops off of the three Stromberg 97s to see if there was any dirt in the bowls and that the needle and seats were OK. I put it back together and I haven't had the problem again (YET). We'll see what happens further down the road. If it comes back I'll start with the coil.
  21. classiccarjack
    Joined: Jun 30, 2009
    Posts: 1,440


    Please let us know if you have a repeat offense and have come up with an solution.

    Sent from my XT1585 using The H.A.M.B. mobile app
  22. 1946caddy
    Joined: Dec 18, 2013
    Posts: 1,689

    from washington

    Had the same problem in my non HAMB friendly pickup with 454 Chevy engine. This went on for more than a year. Driving down the road and all of a sudden the engine wouldn't be running and the first clue would be the power steering gone out and no power brakes. After coasting to the side of the road, it would start up immediately and be fine for several months and do it again. I soon developed a electrical problem with the engine quiting on me when I hit the brakes or turning on the lights and this was cured with a new alternator. I replaced the fuel filter and thought I had fixed the problem but a few months later, same problem. Next replaced the ignition module and coil and it seemed OK for a few weeks and then it quite on me and wouldn't start. After waiting for several hours, it started right up and ran fine. I then replaced the fuel pump in the tank and it's been two months without a problem.
  23. sloppy jalopies
    Joined: Jun 29, 2015
    Posts: 4,136

    sloppy jalopies

    shucks, that's just some young buck's mom and dad having put a governor on the old beast....
    probably $7.64 at your local western auto... $9.95 installed

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