I have 1998 a Lincoln Town Car with the same problem.. It idles rough when you start, then smooths out once it warms up and you give it gas. From what I am reading its either an oxygen sensor or you have vacume leak in one of your hoses by the manifold.
Morgan
The 1998 Blazer could have several problems causing rough idle. Check the air filter, fuel pressure, and EGR valve for a clog to look for the problem.
why does my vr commodore idle rough when at complete stop
Why does my 2001 kia sportage idle rough?
rough idle smell gas
With mine, the rough idle was fixed by changing the spark plug wires.
check dist. cap for water
The Dodge ram 1500 rough idle can because by a bad spark plug or spark plug wire. The rough idle can also because by a bad camshaft.
When the idle goes rough, you must idle the plugs. Else the car plugs roughly.
If an alternator is going bad it can cause a rough idle in a 1993 Subaru Legacy. Cold temperatures in the winter can also cause a rough idle in the Subaru Legacy.
yes mine had a really rough idle and it turns out the motor mount needed replacing
check pcv hose elbow for vacuum leak.