68 chevelle no spark
68sschevelle
07-30-2006, 03:35 PM
:banghead: Hey has anybody seen this one on my 68 chevelle I know the coil is good but I cant get spark, key on 12 volts, key to run 12 volt I pulled the high tension lead put it close to ground - nothing -any ideas
maxwedge
07-30-2006, 03:53 PM
Welcome to AF. When cranking the engine what is voltage at b plus on the coil, if none jump 12v to it and see if it starts. If good voltage when cranking, remember it is resisted in the harness to about 7-9v, points condenser, rotor, or bad wire to points.
68sschevelle
07-30-2006, 04:34 PM
Hey thanks for the reply on my 68 impala I noticed key on 7.2 volts to ground, key in start 12 volts On the chevelle everything appears stock, points wiring etc, key on 12 volts I know the coil is good I swapped it to the Impala no problem But back on the chevelle I cant get a apark from it
corning_d3
07-30-2006, 05:00 PM
Any coil reading 7/12 volts on the negative side isn't a good coil.. or the ground is shorted to voltage..
Blue Bowtie
07-30-2006, 05:37 PM
...Unless the points are open. If the engine happened to stop with the points open, there will be voltage on the negative side of the coil.
Have a dwell meter? That would be a quick way to see if the coil has proper voltage at cranking and the points/condenser are working.
Have a dwell meter? That would be a quick way to see if the coil has proper voltage at cranking and the points/condenser are working.
68sschevelle
07-30-2006, 05:57 PM
Let me clarify the best I can,
On my68 Impala which runs fine doing voltage checks I notice at the positive side of the coil key on (car not running)7.2 volts (car running 7.6 volts and in starting a whopping 12.2 volts
now for the chevelle That I just got (not running) the same checks showed key on (not running) 12 volts positive side and 9.6volts cranking positive side,the battery works just fine in the Impala as well. I took a jumper from the neg- side of the coil and quickly tapped it to ground (key on and I get spark) I tried 2 different distributors and dont get spark to the plugs, the cap is good tried new points and condenser
I know its probably something simple that I just over looking and I probably need to take a break I feel like Im going in circles check check check and more swapping and checking
well any ideas would be great at this point
On my68 Impala which runs fine doing voltage checks I notice at the positive side of the coil key on (car not running)7.2 volts (car running 7.6 volts and in starting a whopping 12.2 volts
now for the chevelle That I just got (not running) the same checks showed key on (not running) 12 volts positive side and 9.6volts cranking positive side,the battery works just fine in the Impala as well. I took a jumper from the neg- side of the coil and quickly tapped it to ground (key on and I get spark) I tried 2 different distributors and dont get spark to the plugs, the cap is good tried new points and condenser
I know its probably something simple that I just over looking and I probably need to take a break I feel like Im going in circles check check check and more swapping and checking
well any ideas would be great at this point
68sschevelle
07-30-2006, 06:04 PM
Thanks blue bowtie I do but have only used it for engine running to (check and set etc.) I will go and try that right now. I have been useing a volt/ohm meter. Thanks
Blue Bowtie
07-30-2006, 08:35 PM
...And?
corning_d3
07-30-2006, 09:57 PM
...Unless the points are open. If the engine happened to stop with the points open, there will be voltage on the negative side of the coil.
I was assuming the point were closed.. My bad.. Did you gap those new points?
I was assuming the point were closed.. My bad.. Did you gap those new points?
alblogg
08-06-2006, 12:26 PM
Did you fix the Prob?
bobss396
08-08-2006, 08:40 AM
I don't bother with any electrical equipment when I have a problem like yours. Most of the time you'll have a bad set of points or a dead condensor. I always kept a spare known-to-be-good coil around just to rule it out quickly.
Bob
Bob
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