I just finished wiring my car with a Duraspark ignition...

I have it wired for a push button starter and toggle switch for the Duraspark. I am also using a TFI coil with a ballast resistor and an Autometer tach.

While going through the salvage yard I came across a TFI coil plug that had two green leads and two red leads. I have it wired so that one red lead receives full 12v while cranking. Once no longer cranking the coil receives voltage through a ballast resistor.

When I flip the toggle switch to turn on the Duraspark I get a loud buzzing noise from the TFI coil. When I disconnect the wire from the starter and depress the starter button the buzzing noise gets louder.

The two green leads from the TFI coil plug go to the tach and to the Duraspark module.

When I flip the toggle switch to turn on the Duraspark, in addition to getting the loud buzzing noise from the coil, the tach pegs to 9000... This of course is without the engine running.

The TFI coil is mounted on a standard TFI coil bracket to the strut tower. The bracket was cleaned and painted prior to being installed.

Any help, suggestions, etc... will be greatly appreciated. I have not tried to fire it up yet, not sure that it would at this point anyway, as I want to get this problem resolved.

The module is a Duraspark II with the blue strain relief.

 

What is the source for "the full 12v while cranking"?

Try disconnecting this wire.

 

Is there a reason why you are using a TFI coil with a duraspark II system? It's not the correct coil for this system, even though it might work.

 

Dave... I have read the TFI coil is a more durable piece compared to the oil filled coil. This is a set up for a Mustang road race car. I am required by the class rules to use a Duraspark ignition. The other folks in the class running carbureted Fords are using the Duraspark with TFI coils from what I can gather.

 

Keep an eye on it. If you start having module failures I would get the correct coil. I suspect your module may have a problem, causing the buzzing. If you have a spare, I would try it and see if the buzzing goes away. Go back to the junkyard and try to find a used Motorcraft box. You should keep a spare and take it with you to the track anyway. You could keep it in the car and swap it on the fly if you have the system mounted inside the car.

 

You should not use a TFI coil with a Duraspark system. Use a Duraspark coil with a Duraspark system which will have the correct primary winding resistance.