low battery cause no spark?
08-14-2012, 09:15 PM
#1
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low battery cause no spark?
hello,
can a low battery cause no spark. battery voltage is 11 volts, car cranks but no spark to the spark plugs. could this be caused by low battery voltage or should i start looking somewhere else?
can a low battery cause no spark. battery voltage is 11 volts, car cranks but no spark to the spark plugs. could this be caused by low battery voltage or should i start looking somewhere else?
08-14-2012, 11:14 PM
#2
Melting Slicks
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Never say never but I think you should look elsewhere.
How did you determine the spark plugs are not getting spark? Did you remove the coil wire and hold it near the block while cranking the engine? If you see a spark jump to the block then it is putting out fire. If it isn't you need to look at the coil and wiring.
Not knowing what year car you have and whether it has HEI or a points type distributor can make a difference in diagnosis.
Is the shielding in place around the distributor? My own experience may be of help. My '69 was cranking and there appeared no fire. I removed the top to the shielding and the car would start. I had my hand near...not touching...the coil and distributor...and a spark jumped to my hand that sent me running to see if my nuts had turned into night lights!
It turned out the coil wire had a pinhole that was allowing the spark to escape and ground out against the cover for the shielding, even though it has a non-metallic insulator in there. I replaced the coil wire and no more problem.
It may be as simple as that for you.
How did you determine the spark plugs are not getting spark? Did you remove the coil wire and hold it near the block while cranking the engine? If you see a spark jump to the block then it is putting out fire. If it isn't you need to look at the coil and wiring.
Not knowing what year car you have and whether it has HEI or a points type distributor can make a difference in diagnosis.
Is the shielding in place around the distributor? My own experience may be of help. My '69 was cranking and there appeared no fire. I removed the top to the shielding and the car would start. I had my hand near...not touching...the coil and distributor...and a spark jumped to my hand that sent me running to see if my nuts had turned into night lights!
It turned out the coil wire had a pinhole that was allowing the spark to escape and ground out against the cover for the shielding, even though it has a non-metallic insulator in there. I replaced the coil wire and no more problem.
It may be as simple as that for you.
08-14-2012, 11:40 PM
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Never say never but I think you should look elsewhere.
How did you determine the spark plugs are not getting spark? Did you remove the coil wire and hold it near the block while cranking the engine? If you see a spark jump to the block then it is putting out fire. If it isn't you need to look at the coil and wiring.
Not knowing what year car you have and whether it has HEI or a points type distributor can make a difference in diagnosis.
Is the shielding in place around the distributor? My own experience may be of help. My '69 was cranking and there appeared no fire. I removed the top to the shielding and the car would start. I had my hand near...not touching...the coil and distributor...and a spark jumped to my hand that sent me running to see if my nuts had turned into night lights!
It turned out the coil wire had a pinhole that was allowing the spark to escape and ground out against the cover for the shielding, even though it has a non-metallic insulator in there. I replaced the coil wire and no more problem.
It may be as simple as that for you.
How did you determine the spark plugs are not getting spark? Did you remove the coil wire and hold it near the block while cranking the engine? If you see a spark jump to the block then it is putting out fire. If it isn't you need to look at the coil and wiring.
Not knowing what year car you have and whether it has HEI or a points type distributor can make a difference in diagnosis.
Is the shielding in place around the distributor? My own experience may be of help. My '69 was cranking and there appeared no fire. I removed the top to the shielding and the car would start. I had my hand near...not touching...the coil and distributor...and a spark jumped to my hand that sent me running to see if my nuts had turned into night lights!
It turned out the coil wire had a pinhole that was allowing the spark to escape and ground out against the cover for the shielding, even though it has a non-metallic insulator in there. I replaced the coil wire and no more problem.
It may be as simple as that for you.
Its a brand new HEI distributor. It was sparking as it was supposed to then the battery got low and it stopped sparking the plugs. that's why i was asking about voltage. maybe once you drop bellow 11.5 volts the HEI doesn't work? the motor is a refreshed motor that was transplanted from a 88 pickup.
verified spark with a "spark tool" (lisile light bulb tool thingy)
Last edited by 69SSC5; 08-14-2012 at 11:53 PM.
08-15-2012, 12:10 AM
#4
Melting Slicks
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Charge the battery (or swap in another battery) and see if things run as they should. That should confirm or eliminate battery voltage as the cause.
If it does, then you have to investigate why the battery is low on voltage.
If it does, then you have to investigate why the battery is low on voltage.
08-15-2012, 12:27 AM
#5
Le Mans Master
Pull the TACH wire out of the cap, clip a 12v testlight to the terminal and while touching the other end of the light to ground, crank the engine. The testlight should flash. That will prove the pickup coil and module. From there, it's the rotor, cap or coil.
08-15-2012, 10:16 AM
#6
Tech Contributor
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thanks for the reply...
Its a brand new HEI distributor. It was sparking as it was supposed to then the battery got low and it stopped sparking the plugs. that's why i was asking about voltage. maybe once you drop bellow 11.5 volts the HEI doesn't work? the motor is a refreshed motor that was transplanted from a 88 pickup.
verified spark with a "spark tool" (lisile light bulb tool thingy)
Its a brand new HEI distributor. It was sparking as it was supposed to then the battery got low and it stopped sparking the plugs. that's why i was asking about voltage. maybe once you drop bellow 11.5 volts the HEI doesn't work? the motor is a refreshed motor that was transplanted from a 88 pickup.
verified spark with a "spark tool" (lisile light bulb tool thingy)
Follow Tim's advice, and let us know what you find.
08-15-2012, 08:05 PM
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ok i charged the battery put it in and turned the key. It sparked once then never sparked again. so thats kinda confusing me. why would it spark once then not spark anymore?
08-15-2012, 08:09 PM
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ok so i did what you said and the test light lights up with the key on and flashes when i crank the motor
08-16-2012, 04:30 PM
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Last edited by MelWff; 08-16-2012 at 04:40 PM.
08-16-2012, 05:20 PM
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08-16-2012, 05:38 PM
#14
Le Mans Master
The test light flashing indicates your module is good. Remove the dist cap and inspect the rotor and the center button in the top of the cap that contacts the center of the rotor. The next likely suspect is the coil.
08-16-2012, 06:23 PM
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ok after attempting to start it several different ways i went ahead and pulled the cap off. the rotor looks new. I pulled the two wires off of the pick up coil to test them. test procedures say you connect one multimeter probe to on of the pick up coil leads and then ground the other probe lead. They say you should see infinite resistance and if not then the pick up coil is bad. I get infinite resistance on one of the pick up coil leads but on the other lead i get 76.1 ohms. so it looks like a bad pickup coil is the culprit.
I come inside do some research on pick up coils then i go back outside 15min later to re-ohm out the coil leads just to quadruple check. well this time both leads show infinate resistance. I am positive before one of the leads was showing 76.1 ohms (i tripple checked). So whats the deal any ideas?
I come inside do some research on pick up coils then i go back outside 15min later to re-ohm out the coil leads just to quadruple check. well this time both leads show infinate resistance. I am positive before one of the leads was showing 76.1 ohms (i tripple checked). So whats the deal any ideas?