91 C2 will only run on one coil
 

my car started acting up the other day and got progressively worse untill it wont run at all.

some experimentation has yielded the following strange results

it runs smoothly if i drive the secondary distributor with the secondary coil. it runs albiet roughly when i drive the primary dist with the secondary coil

it runs smoothly when i drive the secondary dist with the primary coil. it wont start when i drive the primary dist with the primary coil

it wont start in the normal 2 dist/ 2 coil condition. (it tries to start but doesn't)

if i drive the coils with each others drivers, nothing happens in any condition....so there is a difference at least in the way the coils are driven

who really knows how this system works???

Simple question, but is the belt broken? I realize the symptoms don't reflect this, unless you have the primary and secondary confused.

no the belt's good