You need to run a ground lead to your motor.
Grounding back at one end of the car and having the starter and all your electrical components at the other end is a bad idea.
I had a friend who learned the hard way, his wouldn't start either.
After buying a new module and coil he finally called and asked me to look at it.
It had too much of a volatge drop to fire the ignition.
It would spin over fine, but no fire, we ended up running another ground wire from the battery to the engine block and then one on the intake, it popped right off after that.
Not saying this is your problem but this is something that many people take for granted, you must have a good ground where all your components are, the frame is NOT adequete.
Sooner or later - grounding your battery on the frame near the trunk will bite you in the a$$.
JMO>Cp