lack of spark

[billy]

iam working on a 1946 studebaker and i have spark at the points but
no spark at the plugs not sure why can someone help. do i need to drop volts to the points?
thanks bill

[uasrs]

It could be several things. You said there is no spark at the plugs...how are you checking this? Using a voltmeter or just grounding the plug to the engine and turning the engine over? Make sure you have the correct rotor and that it's contacting the distributor cap under the coil wire. Also, make sure the dist. cap is correct and not too tall.

[billy]

grounding the plug to the engine and put on a new dist cap everthing looks good.

[Dick Steinkamp]

A stock, 6 volt positive ground system, will not have a resistor to drop the voltage to the coil.

The hot wire from the ignition switch should go to the - side of the coil. The wire from the distributor should go to the + side of the coil.

Test to see if you have 6V on the - side of the coil with the ignition switch on. If not, the switch and/or wiring need attention.

If so, test to see if you have 6V on + side of the coil with the points open and 0 V with the points closed. If not, the problem is with the points, point gap, distributor wiring.

If so, it is wired correctly and the points are working correctly. test the coil by cranking the engine with the ignition on and with the coil wire disconnected from the distributor and held close to a ground. You should get a nice fat spark. If not, the coil is bad.

If so, the problem is with the cap, rotor, or wires.

Dick Steinkamp
Bellingham, WA

[Milaca]

Are the points new? If not, you could be getting inconsistent spark at the point contacts if they are a bit dirty. I had this issue this summer until I filed the contacts, then I had hot consistent spark jumping between the contacts.


Brent's rootbeer racer.
MN iron ore...it does your body good.

[billy]

i have changed to 12 volts and filed the points and have taken a voltmeter testing to make sure plug wires are working

[Milaca]

New rotor installed?


Brent's rootbeer racer.
MN iron ore...it does your body good.

[buddymander]

An easy test is to turn the engine so the points close, then with the ignition on, take a plastic spoon and open the points. Make your test at the coil wire, not the plug wire. Take the end out of the cap and hold it close to ground. Every time you open the points, you should get a spark.

[billy]

no to a new rotor but do i need to reduce the volts from 12 to 9 volts to the points?

[Dick Steinkamp]

quote:Originally posted by billy

no to a new rotor but do i need to reduce the volts from 12 to 9 volts to the points?

You need to provide 12V when cranking and 6+ V when running.

If you've switched to - ground also, the feed from the ignition switch goes to the + terminal on the coil and the distributor goes to the - side.

Did you replace the coil with a 12V one?

Dick Steinkamp
Bellingham, WA

[buddymander]

Yes, you do need to reduce the volts. And you need to install a twelve volt coil. I wouldn't reduce the volts just yet. First get it to run on full twelve. Most engines crank at twelve volts to the coil and then switch over to 9. Make sure that the low voltage going from the coil to the distributor is the same as the battery ground voltage.

[buddymander]

Oops, Dick was posting when I was typing..And I agree except I wouldn't try to get the voltage perfect just yet because if you have it too low, it won't start. Just don't run it for more than a few minutes without installing the correct resistor.

[studeboy28]

The mantra I learned as a kid fixing tractors was. Spark at the point but not at plugs, replace your condenser.

28 dictator
40 commander

[billy]

i do have a 12 volt coil and i will change the condenser i will try all thank you and i will let you guys know if it works
thanks bill

[billy]

thanks guys i did change the coil and did get good spark
just wanted to say thank you for all your help
46studebaker