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Discussion Starter #1
I bought a '64 1/2 D-code 289 hardtop a couple years ago mainly because it had a very well-built drivetrain and a great suspension setup that I wanted to remove and use on another car. I am just completing the task of returning the car to its stock condition and have run into a very weird problem I thought was just a fluke. I was obviously wrong.

I had the car stored at a friend’s for a little while. He drove it once and found it was cranking a little hard after he returned home. It got to the point where it wouldn’t fire with the Mallory Unilite distributor and Powermaster coil. I switched to a stock distributer and changed the coil everything seemed fine.

I drove the Mustang home last year (about 30 miles) and parked it in front so I could move my daily driver from the driveway. When I went to start it (after sitting for 2-3 minutes – no more) it would crank strong but wouldn’t fire at all. It was getting fuel so I went to check for spark and after a few zaps against a shock tower brace bolt it almost fired. I put the plug wire back on and it fired right up.

Fast forward to this weekend. The car is now back to its stock guise with a different drivetrain and all normal suspension and such in place. I never touched the voltage regulator and only unbolted the generator from the old engine and installed it on the “new” one. I did the final adjust on the valves this weekend so the car got good and hot while doing so. I went to fire it up about half an hour later and it did the exact same thing as before – crank like crazy but wouldn’t fire. I had been using a funky aftermarket coil and was going to change it anyway so I put on a known good, original style coil and still no go – all crank, no fire. Once again, when I went to check for spark, on about the third zap against the bolt the car acted like it was going to start. Put the plug wire back on and, sure enough, it started right up. It also did this a second time after returning from a drive.

What the heck is going on here? This only happens when it’s hot. When the car is cold it cranks and fires fine every time. When it’s hot you can shut it off and fire it back up right away. The problem appears if the car sits hot for a minute or more. It’s obviously getting spark but it acts like it isn’t and when you go to check for spark (screwdriver in plug boot held next to metal) it wants to fire. Sounds like a generator or voltage regulator problem but what, exactly? Any clues?
 

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Sounds more like a carb problem. Where is the choke plate when you try to start it hot? If you have percolation in the fuel bowl, gas will drip into the intake causing a flood condition. The "start it up right away" does not allow time for the fuel to build up too much. Minutes later it has. Are you using the 1 inch carb spacer, or is the carb bolted directly to the intake?
 

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Discussion Starter #3
Yes, the Holley carb (electric choke) is something I transferred over (for now) from the other engine. I haven't yet tried an Autolite 4100 on the car but the Holley was on both engines that exhibited this same symptom. I'm using the standard 4V spacer.

But why would it want to fire while checking for spark and then start fine after doing so? That's the thing I just don't get. Is that somehow giving the system an extra "jolt" somewhere along the line, convincing it that it's time to start?
 

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As she spins, she pumps. (err...we'll leave that alone :-0 ) Eventually the flood condition is relieved. Pulling the wire just gave you something to do while waiting for it to fire.
 

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Discussion Starter #5
Pulling the wire just gave you something to do while waiting for it to fire.

I wish that were the case, but it absolutely will not fire until I check for spark. It will crank and crank and crank and crank but not until I actually pull a boot, put a screwdriver in it, hold it against the shock mounting brace bolt and then crank the engine will it begin to even want to fire. I still need to try the Autolite 4100, but I just think it goes a little deeper than the carb (but, oh, how I hope that it could be :). At least then I'd know.
 

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Got a good engine ground strap? The heat would make the connection more resistive making less spark which would agree with 66conv6's assesment. Your connecting it (or referencing it) to a low impedance ground (shock tower bolt) could wake the spark back up enough to maintain firing. clean the connections and get a new strap if your old one is corroded.
 

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Discussion Starter #8
Got a good engine ground strap?

Hmm, interesting. Actually, it is the same ground strap that was on the car before and, hence, could be a contributing factor in this dilema. It's a braided-style 6" battery cable that was attached from the block to the motor mount. I've since moved it up to its traditional placement - firewall to right rear cylinder head. It looks fine but I'll get a new ground strap and see what happens.

Thanks guys.
 

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i have the same problem with mine, but it is not very often. usually when i'm getting gas, a coke, or putting air in the tires. it really seems to be a carb problem, and basically seems to be flooded. i find that if it doesnt start after one or two cranks then push the gas pedal down to the floor and hold it while cranking, it usually does the trick for me, if my car has only been sitting for a few minutes.
 

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Yeap, get a good short engine ground strap......

make sure your starter and battery cables are kosher as well.....
clean all conatacts on your ignition system......

cap, rotor, coil etc....

also clean your battery posts and coat them with terminal coating.

good luck
 
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