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Discussion Topic:
ignition coil testing
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Kens 36 |
05-06-2014 @ 11:43 AM
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Member
Posts: 347
Joined: Oct 2009
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Skip Haney 29436 Taralane Dr Punta Gorda, FL 33982 Email: skip@fordsrus.com Day:941-637-6698 Night: 941-505-9085 Ken
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Chascwell2 |
05-06-2014 @ 11:01 AM
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Member
Posts: 35
Joined: Feb 2014
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How do I find Skip Haney, the coil rebuilder
chascwell
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TomO |
05-06-2014 @ 6:20 AM
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Senior
Posts: 7256
Joined: Oct 2009
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You are driving the best coil tester. Check your spark with the engine idling when it it running good and when you are having problems. A rebuilt Ford script coil is the best way to go. The aftermarket coils do not seem to hold up very well and a NOS or NORS coil have probably deteriorated insulation and will fail when hot.
Tom
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cliftford |
05-05-2014 @ 7:24 PM
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Senior
Posts: 845
Joined: Jan 2014
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Supereal's comments reflect my experience. The coil is the most unpredictable componet on these old V8s. Play it safe and get a rebuilt ciol.
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supereal |
05-05-2014 @ 5:30 PM
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Senior
Posts: 6819
Joined: Oct 2009
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The normal voltage at the coil input should be about 3.5 volts if the resistor is functioning. If your coils are original, unrebuilt type, it is very likely they are defective, or very weak, particularly when hot. Testing windings with an ohmeter will only confirm the winding is intact. The readings of a new or rebuilt coil are .47 to .51 ohms at the primary, and a secondary resistance. of 5800 ohms, with measurements made at 68 degrees F. A coil tester is usually not helpful. Shorted windings and deteriorated wax paper insulation render a coil ineffective. Resistance is not indicative of condition because it doesn't measure reactance or capacitance. Most of us send coils to Skip Haney to be rebuilt with modern materials.
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Chascwell2 |
05-05-2014 @ 12:34 PM
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Member
Posts: 35
Joined: Feb 2014
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I am also experiencing a bucking problem after running for a few miles and getting the car warmed up. The carb has been overhauled and cleaned, the fuel pump checked for output pressure, the distributer has been overhauled, new points and condensor, lubed and adjusted and new caps and wires. I have three ignition coils and a multimeter. Each of the three coils has zero resistance on the primary side and varying resistance on the secondery side, up to 34,000 Ohms and as low as 14,000 Ohms. Does higher secondery resistance result in more voltage output? In the old days I could check out secondery voltage with an ocilliscope on 60's vintage cars, is there any way to check the output on one of the early coils? Has anyone experienced "Coil breakdown" as the engine warms? It has a new resister in the ignition circuit, the voltage at the distributer reads 6 volts when the points are open and 4.5 when they are closed.
chascwell
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