308FI Weak spark,9.5 volts at coils Help!

I know little about the ign system on your new-fangled car <g>, but most systems have a resistor somewhere in the primary side of the coil circuit. Check your wiring diagram to make sure. The voltage may be normal.

Otherwise, do the usual check of wire connectors, fuse/fusebox (if applicable - on my 1975 the ignition doesn't actually flow thru a fuse, but does connect with some other wires at the fusebox), and ign switch. The switch contacts could be providing some resistance.

 

There are two ceramic blocks under the coils. Usually painted red. These are the ballast resistors. Voltage to the coils goes through these resistors. 9.5v at the coil is normal.

Have you checked your distributors? Dwell, timing, etc? Also the points in the distributor can be adjusted to make sure the spark is delivered to the rotor just when its pointed at a cylinder pin in the cap. It is possible to have the points mispositioned so the spark is delivered to the rotor as much as 10 degrees off.

 

Check the plug wires at the dist. cap. Sometimes they are not inserted all the way into the terminal. Reinstall after using a little grease on the wires

 

Pnorman.
Keyed voltage at the coil will be 9.5 after it has passed through the resistor.
With a spark plug , plugged into the plug tower resting it to ground on the motor cranking the motor the spark is decievingly weak but is normal.
If you want Fried chicken spark change to 2 Bosch blue coils.
Let the car sit overnight if you have been cranking the car over and over if the plugs get soaked with fuel it will not start this happens with not a lot of cranking.
Crank motor with no throttle imput.
Crank speed has to be up as if the battery is weak you will be wasting your time.
Good Luck
Kind Regards
Wayne Hynes.