Intermitent Idling Problem

I have a 1989 Lebaron convertible with a 2.2 turbo auto trans.
Here is the problem:
Sometimes after sitting overnight it is hard to start and once it does it will not idle on its own. If I keep my foot on the accelerater or put it in drive with one foot on the brake and other on the gas and drive for a block I hear a click and it will idle on its own(And run like a top). The problem is intermitent and may not return for a week or more.
I replaced the fuel pump not long ago but it had the same problem before the pump went. Also have replaced the fuel filter.
Any help appreciated.

most likely it is the computer trying to get the air-fuel mixture right. Once the oxygen sensors get hot enough to operate, then it will go into closed loop mode and run right cause it is using the oxygen sensor to determine the fuel mixture.