what causes idle hunting, idling between 1200 and 1000, also car always has some bucking while driving at 30 mph, or city driving

 

How do your AFR numbers look? Have you checked your O2 sensor? I believe the new O2 sensor that I installed with my cooler thermostat and rad fan switch fixed my short lived idle hunting/bucking issue a few years back.

-Colin

 

Lets start with this. What year is your car? Any recent repairs or other known issues? Sounds to me without knowing the previous info, that its a throttle position sensor that's misadjusted or failing.

 

I agree, or a new vacuum leak from said recent repairs

 

textbook vaccuum leak, unfortunately there are a ton of sources. Best bet is to use a fogger to find the culprit.