Could It Be the Ignition Coil?

[peche 71]

As a follow up to one of my previous post: I'm still not getting a start. We diagnosed and replaced the ignition switch, thanks to all the previous guys for the suggestions.

So, in addition, the carb was rebuilt, and I put in new: battery, solenoid, plugs, wires, rotar, condensor, cap, points, and fuel filter. It'll turn over but that's it. I tried some gas in the carb and starterd fluid but it doesn't help. The ignition coil is not leaking, otherwise I'm not sure how to tell if it's bad. The battery is fully charged.

Any help would be greatly appreciated.

 

[TheRktmn]

To bench test the coil with a multimeter: http://autorepair.about.com/od/troubleshooting/ss/coil-test-ohm.htm

The coil needs voltage going to the + side to charge and the ignition system (points/elect) to discharge (spark).

Do you have spark coming out of the coil?

If yes, check the coil wire from coil to cap and the cap & rotor. I have seen rotors removed and forgotten, burned and even the wrong rotors installed. Visually inspect the cap for burns, cracks and carbon traces that can cause shorts.

If no:

With the key ON, what is the voltage at the + side of the coil?

If nothing, check the resistor wire from the key to the coil.

What is the voltage at the coil + terminal when key is in START position?

If nothing, replace the starter solenoid (the I terminal of the solenoid supplies battery voltage to the coil during starting)

Do you have points or electronic?

If points, check the gap, visually check that the points are opening & closing when motor is turning over.

If electronic check per the manufacturer's troubleshooting guide.

 

[rpmcarter]

off the cuff....what he said

 

[73vertproject]

Yep, check for spark at the coil wire to cap, and then go either upstream (toward the battery cable if no spark) or downstream (toward the spark plugs if there is spark) from there.

 

[hyena429]

If you really wanna trouble shoot your coil with out a voltage tester....one easy way......Unhook the positive wires going too your ignition from the coil.... Hook a wire from your positive bat terminal too your coils positive side..If you get spark and it starts...You know your coil is fine....But i would not leave it like that for long..its just for testing...I had to do that too a little mustang 2 with points.

Another easy way too...pop the cap on your distribitor...Turn your key on run...and with a screw driver touch where the point and contact meet...it should spark a little when you do.....If your coil is bad..It wont do anything.....These are only quick checks and fixes for folks who mite not have a voltage tester.

 

[peche 71]

great suggestions, thanks Guys!

 

[Tnfastbk]

You can just hook your timing light up to your spark plug wire. spin her over and see if she is firing.

 

[peche 71]

well it's not the ignition coil. I installed a new one today, and it makes no difference. the money pit gets larger!

TNFastback, i did have one of my guys do that after we installed the ignition switch and there was some spark, not much but some, it was after hat I replaced the plugs, wires etc.

 

[Tnfastbk]

well it's not the ignition coil. I installed a new one today, and it makes no difference. the money pit gets larger!

TNFastback, i did have one of my guys do that after we installed the ignition switch and there was some spark, not much but some, it was after hat I replaced the plugs, wires etc.

Hmmm only need 3 things fuel, fire and air. Should run. May run terrible but should start

 

[don29163]

If you replaced the coil and the spark is still weak, you may have a bad condenser(even if it is new)

http://autorepair.about.com/cs/generalinfo/a/aa052502a.htm

 

[Don C]

Missing ground wire from points to distributor body can cause similar problems.

 

[peche 71]

thanks Don C and Don, i'll look into those ideas.