I think I have narrowed my problem down to my opti-spark. When I call around to see who has the best price on a new one, they give me the price on two things....the first being the opti-spark and the second one being a control module. What is the control module, and should I go ahead and get a new one? Its only like $80 so it's really not that expensive. My car is a 94 Z-28. Thanks!

 

Apparently you can buy pieces separately, from places other than GM (you said you called around, you didn't say whether that was GM or other places), like just the rotor and cap etc... This control module could also be the ignition control module, which isn't part of the opti.

Its been my experience that you should ONLY buy a GM unit, and ONLY buy the complete unit. There is however, a new company that is selling billet aluminum ones with upgraded parts. Worth checking into. Last I checked they did not have the non-vented one for our year, just the 95 or 96 + one.