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Discussion Starter #1 (Edited)
I added to someone's thread that I am having the same issue as he was. Car starts up no problem when first started in the morning. But after an hour or so, it'll take about 10-15 seconds cranking before it starts up again. Well, it did that today and just now, it won't start at all. It'll crank but that's about it. I know some of you will say timing, etc. but it's not the timing. So my question is, how can I tell if my coil is the issue? I have the msd blaster coil.

P.s. There is gas going to the carb. I kind of had the issue before and it seemed like it was the power valve. But I want to make sure the coil is even functioning properly.
 

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The coil wont work "part-time." Its an all or nothing deal. ill bet dollars to donuts you have a flooding issue:)
 
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The coil wont work "part-time." Its an all or nothing deal. ill bet dollars to donuts you have a flooding issue:)
That is not totally true. A coil can operate when cool and then when hot it can stop working. This is because you can get small breaks in the internal windings that will expand and no longer pass current when they become hot. This is a common failure among automobile electrical parts that contain windings. The first test you can make with a coil is to check continuity. It is not the end all test, but it will show if you have an open circuit. Checking both primary connections is where to start. But the true test for a coil involved a small tester called a growler. Most people or even shops do not own one. It puts the coil into operation mode and tests it then.
You should first check to see if you see a spray of fuel in the venturi when you move the throttle linkage. That will tell you if your fuel bowl is full ( give you a good idea anyway ). Then see if the choke plate is totally open. I'm betting it is a carburetor issue of some sort, but it could be ignition related.
 

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The coil wont work "part-time." Its an all or nothing deal. ill bet dollars to donuts you have a flooding issue:)
Not true. I've seen many a coil break down with heat and some that were so weak that they'd start hard and wouldn't make a good spark under load..cause backfiring, etc.

Using an ohmmeter, check the resistance of the primary and secondary circuits of the coil. To test the primary, connect your red lead to the + and your black lead to the - terminal. You should have approximately .7 ohm. To test the secondary, connect your red lead to the + and your black lead to the high tension terminal (tower). You should have approximately 4.5k ohms.
 

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I'd throw it out and buy a new one. If the problem still is there then it was good

Of course you can borrow a known good one and check that way.
 

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I had a bad coil on a friends Chevy drive me crazy for a couple of months. I kept thinking it was the three deuce Strombergs. Turned out the bogging at WOT was the coil cutting out. Stupid FlameThrower was a couple of months old.

I don't think its your coil, but you can take it to Auto Zone and have them test it. I'm thinking its timing or carburetor. It could also be some kind of vapor lock.
 

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I did a hot start problem post a while back. I'm still having the issue but now I just kick over the engine with the key off using the start button. After 2 or 3 seconds I can turn the ignition on and it will bust right off. I have a new MSD blaster 3 coil. It was doing it with the old MSD blaster 3 coil too. It is not the coil in my case but I have seen hot coils do this.

If mine were flooded I would expect to see smoke when it finally does crank but there is no smoke at all. I still haven't gotten over to the only gas station in 40 miles that still sells non-ethanol gas to see if that will help the problem.

My fuel line from the fender panel to the carb is stainless braided and not on anything hot but I got the insulating wrap and wrapped it anyway. Perhaps that helped it a little bit. I'm not sure. I don't know what is causing the problem.
 

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I haven't had any luck with Blaster coils.
been thru quite a few over the last 25 years

then one day i had a revalation.
See Ford mounts them horizontally and since theyre oil filled they need to be mounted verticley as stated in the instructions.

I wanted a stock look so I never mounted them correctly
.
I since went with the MSD high vibration coil thats sealed and haven't had any more coil issues.
 

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Discussion Starter #9 (Edited)
Now I'm going to test the coil later today. But one thing to add is I always remove my coil wire off every night. Can taking it off and putting it on every day have some wear to the connection inside the coil nipple cause ing my car to just crank but not start?

P.s. 40 min later After posting this post, I just went out to start my car and started up with NO issues. I'm leaning toward a coil issue as stated above the possible reasons why it can be the coil.
 

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Check your ignition switch and resistance wire to be sure that they are OK. I've had bad ignition switches that have had intermittent poor internal connections to the point where minimal voltage was getting to the coil causing ignition problems.

You can check the primary coil voltage across the coil posts (with points or other pointless device closed circuit). You should be seeing something in the ballpark of 6 to 9 volts.
 

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Now I'm going to test the coil later today. But one thing to add is I always remove my coil wire off every night. Can taking it off and putting it on every day have some wear to the connection inside the coil nipple cause ing my car to just crank but not start?

P.s. 40 min later After posting this post, I just went out to start my car and started up with NO issues. I'm leaning toward a coil issue as stated above the possible reasons why it can be the coil.
No, but it certainly can screw up that high-carbon center conductor in your coil wire. I'd test your coil wire with an ohmmeter while flexing the end to see if there's an internal break. In any case, I'd probably get a replacement coil wire since they're inexpensive anyway.

Do you pull your coil wire as an anti-theft measure? There are much more subtle ways to disable the ignition system that would be almost impossible to spot or override, even to a thief with a jumper wire.
 

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Bartl - great info. I just checked an old one I have laying around it was 1.9 and 6.9k respectively. Will it work for a while? I have been unemployed for 7 weeks now and am trying to put the engine and transmission back in. I will most likely have to move a bit away from home for a while to find decent work and so I would like to have the car back together....no funds available of course...
 

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Discussion Starter #13
No, but it certainly can screw up that high-carbon center conductor in your coil wire. I'd test your coil wire with an ohmmeter while flexing the end to see if there's an internal break. In any case, I'd probably get a replacement coil wire since they're inexpensive anyway.

Do you pull your coil wire as an anti-theft measure? There are much more subtle ways to disable the ignition system that would be almost impossible to spot or override, even to a thief with a jumper wire.
Funny that you mentioned this. My buddy just told me the exact same thing. I do pull it off every night before I go inside. So what he suspects as well as you just said was because the coil wire is sensitive when pulling it off. So maybe doing it many times finally taking toll on my start up. I'm off to get new wires!
 

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Bartl - great info. I just checked an old one I have laying around it was 1.9 and 6.9k respectively. Will it work for a while? I have been unemployed for 7 weeks now and am trying to put the engine and transmission back in. I will most likely have to move a bit away from home for a while to find decent work and so I would like to have the car back together....no funds available of course...
Resistance should be 10-15k ohms per foot of length....or are you talking about the coil? Your readings aren't that far out of range and if it's a "performance" coil with more secondary windings a higher resistance should be expected. A primary resistance of 1.9ohm is pushing it, but still acceptable. Over 2ohms and I'd toss it. Hard to say what might happen when it gets hot....
 

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OK - Thanks...it won't be getting very hot. Yes the coil. No clue where it came from. I was working when I sold the 1967-68 .030 over 289 that used to push the car around. I let it go with everything from the carb (2 barrel) to the oil pan and front to back. I thought I would be buying all new/good parts....wrong I was!
 

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I'd throw it out and buy a new one. If the problem still is there then it was good
Man I love this hi-tech troubleshooting analysis...
 

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Discussion Starter #17

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That is not totally true. A coil can operate when cool and then when hot it can stop working. This is because you can get small breaks in the internal windings that will expand and no longer pass current when they become hot. This is a common failure among automobile electrical parts that contain windings. The first test you can make with a coil is to check continuity. It is not the end all test, but it will show if you have an open circuit. Checking both primary connections is where to start. But the true test for a coil involved a small tester called a growler. Most people or even shops do not own one. It puts the coil into operation mode and tests it then.
You should first check to see if you see a spray of fuel in the venturi when you move the throttle linkage. That will tell you if your fuel bowl is full ( give you a good idea anyway ). Then see if the choke plate is totally open. I'm betting it is a carburetor issue of some sort, but it could be ignition related.
That is not totally true. A coil can operate when cool and then when hot it can stop working. This is because you can get small breaks in the internal windings that will expand and no longer pass current when they become hot. This is a common failure among automobile electrical parts that contain windings. The first test you can make with a coil is to check continuity. It is not the end all test, but it will show if you have an open circuit. Checking both primary connections is where to start. But the true test for a coil involved a small tester called a growler. Most people or even shops do not own one. It puts the coil into operation mode and tests it then.
You should first check to see if you see a spray of fuel in the venturi when you move the throttle linkage. That will tell you if your fuel bowl is full ( give you a good idea anyway ). Then see if the choke plate is totally open. I'm betting it is a carburetor issue of some sort, but it could be ignition related.
Some excellent information in the above posts. I recently had a coil failure while driving my Mustang (1966, 289, reproduction yellow top coil, several years old). The car had been starting a little hard for several months, but ran fine. I had driven it for about an hour and pulled up to a stop light and the engine stalled. And that was it, it would not start. Several people helped me push it into a parking lot. I had a spare Pertronics 11 module with me and changed that out which made no difference. I had gas at the accelerator pump discharge. Vapor lock was suggested by someone in the gathered crowd, but it wasn't that (I do not believe in vapor lock on a stock "modern" car). I grounded the output of the coil to the engine block and there was a very short weak, white spark (should be a strong blue spark, 1/2 inch long). I then called Hemmings for the tow truck (great response & tow). Once home, I installed an old, used Delco coil and the engine started right up, better than it had started in a long time. I measured the primary and secondary resistance of the yellow top coil and the Delco coil, they were essentially the same. The "Growler Coil Tester" mentioned above, I think is what would be needed to test a coil e, but it is probably cheaper to replace the coil unless someone will test it for free. Unless you have a completely open circuit, resistance isn't going to tell you much about the condition of the coil.. I think heat is what finally caused my coil to fail. I installed a new Pertronix 11 flamethrower coil. The car runs great now.
 

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You could also drive the car until you have the problem and then pull off the coil wire, ground it and watch for spark. No spark would certainly confirm the diagnosis.
 

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I kinda' agree with the hi-tech testing. However, there's as very simple way to troubleshoot. When it won't start, but cranks, connect a spark plug tester between the coil and distributor cap. Crank the engine to see if there's a spark. End of test.
 
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