22c12 or 13c12 coil? 1976 XJ12
 

I have the opus system and am chasing gremlins. The WSM calls for a 13c12 coil. My new to me car has a 22c12 installed. The WSM says it is unacceptable to run a new style heavy duty coil with an older AB3 ballast. Here is the installed coil, does anyone recognize if it is a heavy duty model? If so it may not be compatible with my ballast.

Thanks,
Seanhttps://cimg9.ibsrv.net/gimg/www.jag...288d3042db.jpghttps://cimg6.ibsrv.net/gimg/www.jag...6b54a40e39.jpg

The coil I used on the PreHE was a simple contacts points spec coil, of 1.2ohm (+ve/-ve probed).

It was always a "use with ballast" coil, as in an R in the part number in Australia. GT40R is the one I use.

Some of the "update" coils are "electronic ignition compatable", and will not work properly on the Opus.

Those numbers you stated do not appear in old Lucas catalogues that I have, so no help from me with that ask.

Check the ohms, +ve to -ve of that coil. If its around 1.2 or higher, I dont see an issue other than age.

That ballast drops the system voltage to about 7ish, for running mode, and has a 12v by pass for start mode.

Ballast coils are NOT a 12v coil, hence the ballast.

Electronic coils, as in the HE engine, are voltage controlled by the Ign Amp Module, which works differently to the Opus. They are generally 0.6ohms approx.

Thanks Grant,

I'm throwing in the towel on the coil issue. Rob at britishvacuumunit.com basically laughed in my face (in my ear?) for spending time and $ trying to keep the opus ignition system when a petronix kits cost just over a hundred bucks.

He's sending me a new vac. unit with the correct ignition curve, I'll buy a Flamethrower coil and all will be perfect with my car forever.

Thanks,
Sean

Sean,

I've moved your thread from General Tech Help to XJ6 & XJ12 Series I, II & III forum.

You've come to a conclusion of the way to go and anyone looking for advice on the same issue would most likely start here and not General Tech Help.

Graham