I bought this car a year ago and it has been working fine.
Now it has developed a stumble or hesitation.  It shows itself
several ways.

At highway speeds the tach is not steady and floats +/- 100rpm
around the target RPM.  
Occasionaly I will feel a bump like I hit
somthing (but it's the engine stumbling).  This afternoon
I was traveling slow in heavy traffic and breaking a lot.
When traffic started moving again the engine quit when I
tried to accelerate. But it immietiatly restarted.

At low speeds the engine will die when pulling away
from a stop if I give it too much gas. Or it will "chug"
(not audibly) a few times.  Mean while the tach is swinging
wildly around +/- 500Rpm around the 1000rpm mark.

Check engine light is off.  Have not had it checked for
codes.  Tomorrow I will check the plugs, change fuel and
air filter, check for break fluid in the booster vacuume
hose. Have it scanned for codes.

Anything else I should look for while I'm at it??

Thanks