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78 HEI Trouble

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Old May 24, 2014 | 08:22 PM
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Default 78 HEI Trouble

What is the safest way to test to see if I have spark?

Last edited by mikep3; May 28, 2014 at 09:27 PM.
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Old May 24, 2014 | 09:48 PM
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Pull a plug wire and stick a screwdriver with insulated handle into the opening for the plug. Hold it about 1/4 inch from engine metal and have someone crank the engine. Look
For spark.
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Old May 26, 2014 | 02:00 AM
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I tried it there was nothing, no spark. Bought a new $126 distributor from O REILLY's, be careful testing with screw driver, my finger feels like I hit it with a hammer!
Thanks for the help.
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Old May 26, 2014 | 07:15 AM
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Originally Posted by mikep3
I tried it there was nothing, no spark. Bought a new $126 distributor from O REILLY's, be careful testing with screw driver, my finger feels like I hit it with a hammer!
Thanks for the help.
Why does your finger hurt?

Pull a plug leave the wire attached lay it on the block crank and look for spark in the gap.
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Old May 26, 2014 | 07:17 AM
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Originally Posted by mikep3
I tried it there was nothing, no spark. Bought a new $126 distributor from O REILLY's,
They are $40 new on ebay with cap.
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Old May 26, 2014 | 08:22 AM
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when I check for spark I put a old sparkplug in the plug wire.let the plug contact metal .turn over the motor.
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Old May 26, 2014 | 10:46 AM
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Originally Posted by mikep3
Whatnis the safest way to test to see if I have spark?
Use your timing light if you have one.
Clamp on the wire you want to check, point the gun at the windshield when you lay it down and crank the engine. If the light flashes at you, then you have spark.
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Old May 26, 2014 | 11:06 AM
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if your finger hurts, you probably have spark
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Old May 26, 2014 | 07:33 PM
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sure it wasn't just the ignition module gone bad?
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Old May 26, 2014 | 08:17 PM
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on 9 volt batterys you put your tongue on it .
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Old May 26, 2014 | 08:43 PM
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My car died in San Diego 10 feet from my sons driveway. With 2900 miles to get home I was thinking that $126 was not a bad price. When testing the old distributor I put a screwdriver in a spark plug wire and tried to ground the screwdriver to see if there was a spark. When I installed the new distributor I tested the screwdriver in the spark plug wire and my finger got too close to the screwdriver.
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Old May 26, 2014 | 10:23 PM
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Originally Posted by terry82
when I check for spark I put a old sparkplug in the plug wire.let the plug contact metal .turn over the motor.
This is what I do too... Its a bit overkill to replace the whole distributor when the coil or module would heave been much quicker to replace since you wouldn't have to mess with timing but hey what's done is done I guess. Since you have to time the new distributor I would think the timing light would be a dead give away whether you have spark.... You did adjust the timing right ?

Last edited by augiedoggy; May 26, 2014 at 10:28 PM.
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Old May 27, 2014 | 08:40 AM
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Default timing setup

I marked the angle of the distributor via the vacuum can port as a pointer anb the valve cover. Now the aluminum valve cover has a sharpie mark on it that is not coming off very easily.
The rotor was marked on the distributor for final position and starting point. I transferred the marks to the new distributor. The new distributor looked like the rotor and position were the same as the old one, and it started jusr fine.
I need to test it today for drivabity. Looking into were to borrow a timing light.
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Old May 27, 2014 | 01:12 PM
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Originally Posted by mikep3
My car died in San Diego 10 feet from my sons driveway. With 2900 miles to get home I was thinking that $126 was not a bad price. When testing the old distributor I put a screwdriver in a spark plug wire and tried to ground the screwdriver to see if there was a spark. When I installed the new distributor I tested the screwdriver in the spark plug wire and my finger got too close to the screwdriver.
You a brave man to drive a 40 year old car 2900 miles
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Old May 27, 2014 | 01:19 PM
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Originally Posted by terry82
when I check for spark I put a old sparkplug in the plug wire.let the plug contact metal .turn over the motor.
The plug or screwdriver should NOT be touching metal. It should no more then 1/4" away from the metal...you want to see an arch traveling from plug to metal...
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Old May 27, 2014 | 01:26 PM
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Originally Posted by mvftw
The plug or screwdriver should NOT be touching metal. It should no more then 1/4" away from the metal...you want to see an arch traveling from plug to metal...
The base of the plug has to touch the block or you will not see anything.
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Old May 27, 2014 | 02:10 PM
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Default 1978

Originally Posted by micks69
You a brave man to drive a 40 year old car 2900 miles
1978 is only a 36 year old car, now it has a new distributor
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Old May 27, 2014 | 02:19 PM
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Originally Posted by 70ZZ3 96LT4
1978 is only a 36 year old car, now it has a new distributor
Funny! I would not drive my 3 speed auto at 75 mph for 290 miles let alone 2900 miles
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Old May 27, 2014 | 03:18 PM
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Originally Posted by micks69
The base of the plug has to touch the block or you will not see anything.
Do you want to see the arc? Are you saying that if you put a screwdriver in the HT wire (spark plug removed), should the screwdriver be touching metal or 1/4" away...
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Old May 27, 2014 | 03:48 PM
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Originally Posted by mvftw
Do you want to see the arc? Are you saying that if you put a screwdriver in the HT wire (spark plug removed), should the screwdriver be touching metal or 1/4" away...
Your talking screw drivers I'm talking spark plugs. Just lay the plug on the block and crank and observe no more to it
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