my 88 5kq (non-t) has a cold

["Block, Paul" <Paul.Block@fortjamesmail.com>]

First of all, thanks to all who helped with my 'check engine light' post
about a month ago.  I (with hand half covering mouth, head hung in shame,
avoiding eye contact) didn't realize that you could pull engine codes on a
non-turbo the same as a turbo.  I never had a need to check codes on my
non-t, and it didn't even occur to me when the light did go on.  Thanks
again. 

This morning while driving to work, temp a balmy 30F, cruising at highway
speed, engine temp still warming up to normal, the car started
missing/bucking (barely holding highway speed).  If I would press the gas
pedal all the way to the floor, it went like a rocket, but as soon as I
would return to (about) 1/2 throttle, it would start missing again.  After
the car warmed up completely, it stopped missing and ran fine.  

Fuel?  Air?  I just replaced cap, rotor, wires and plugs about 5k mi ago.
Any ideas are welcome and greatly appreciated, as I will be digging into
this one tonight after work.

tia
-Paul