Problem, if I have the tach hooked up the car wont turn over. If I pull the wire from the dizzy (neg side) the car starts right up. I have check the coonections at the tach and all seem fine. I also have switched tachs and same problem.

the tach wire is grounded somewhere between the dizzy and the instrument, either on purpose (anti-theft switch some PO installed?) or due to fraying and wear.