Join Date: Mar 2002
Location: Austin, TX, USA
Sounds like you're not running a balast resistor or resistor wire. I presume you're running a breaker point ignition.
Usually there is a resistor wire running from the main wiring harness connector on the firwall to the coil. A lot of people who run HEI ignitions, will cut this resistor wire and splice on a length of plain ol' copper. The copper wire delivers a full 12 volts for HEI ignitions.
The resistor wire or ballast resistor reduces the running coil voltage to about 9 volts. But, breaker point ignition systems (on Camaros at least) have another wire connected to the positive terminal of the coil which connects to the starter solenoid wire. The second wire provides 12 volts to the breaker point coil only during cranking to give a hotter spark.
Actually the starter connection also gave the coil about 9 volts because the electrical system voltage drops to about 9 - 10 volts during cranking anyway. But thats beside the point.
If you are running breaker points, use the information above to figure out what you have. The firewall connector is relatively easy to disconnect -- there is a 3/8" (or is it 7/16") bolt in the middle. If you use a digital volt meter, you should be able to measure the resistance between the firewall connector and the + coil. Last time I checked one, the resistance was about 2 ohms.
68 Coupe, 350 w/ Edelbrock Performer RPM heads, cam, intake, 700R4, Dave's small body HEI