Solved weak spark thanks for the help

[toddr124]

As some of you know I have been replacing a heater core for the last several weeks will not much success. I went out side to start the car and it will not start. Revs fine. checked the coil wire and only a very weak spark. Checked the voltage at the coil and it was 7.9 volts. Trace the wire back and the is a white something that the coil 12 volt plugs into.

I am getting 11.9 volts on one side and 7.9 on the other. I know my battery is low from thing to start the car. This explains the 11.9, but what is the white thing and why am I getting 7.9 on the other side of it?:dead:

I had never changed the cap or rotor in 35,000 miles. Cleaned them and it is working. I hope this is the real problem.

 

[Pete Whitstone]

That's called a "Ballast Resistor" I think...

and yes, it is supposed to knock the coil voltage down to about 8 volts. This is to keep the points from burning up after a few hundred miles, which they will do if you ran the full 12 volts to the coil.

Pete

 

[roadbox]

and yes, it is supposed to knock the coil voltage down to about 8 volts. This is to keep the points from burning up after a few hundred miles, which they will do if you ran the full 12 volts to the coil.

No points, Pete. Todd's ignition is electronic.

John O.

 

[Black-Tooth]

Todd... sorry for your trouble...

The Ballast Resister is OK and your input voltage is low... I suggest a charge or jump from another battery...

It appears you do have spark... now ya need to prove ya got fuel. Dump or squirt some gas down carb or into AFM and try again. Any POP right or wrong now would indicate you have a fuel problem.

(If ya want... you can "remove" the ballest resister (BR) and tie both wires together to see if the hotter spark might help... but then reinsert the BR again as you will eventually overheat the coil and burn it out.)

You can also try a can of STARTING FLUID (ether) used for deisels and see if that works.

Otherwise... ya gotta look at timing and other issues... try the fuel thing first, let us know.

 

[toddr124]

new symtom Only 1.2 volts on the other side of the coil

I called John O. and he is getting 6 volts on the other side of the coil.

What voltage should I get on the other side of the coil?

I charged the battery and the voltage is better before the ballast resistor.

 

[budgetzagato]

Coil resistance?

Have you checked the coil primary and secondary resistance?