Grumpy lumpy hot idle or restart
It can be a couple of things cheap to dear.
Check the spark plugs for fouling --start it up and when it shows this symptom shut it down and pull all the plugs and check for foulded ones. Could be:
1) just dirty plugs too cold for your driving,
2) worn valve guides allowing oil into the cylinder, fouling plug
3) cracked valve stem seal - see above,
4)leaking fuel injector dripping a couple of tablespoons of gasoline into that cylinder when at rest (most likely culprit)
5) Leaking fuel distributor diaphragm dripping gasoline into intake manifold plenum, causing very rich mixture on restart