Check your vacume hoses too. I had a similar problem when one of my vacume hoses came lose.

 

it was the ignitor in the distributor causing the tach insanity, and then yesterday AM the distributor started squeeling and that convinced me it was time to replace it. turns out the bearing inside the distributor practically locked up making it incredibly hard to spin the rotor.. and giving me my issues... i replaced it and 170$ later problem solved. thanks everyone