Chrysler Repair: 1988 New Yorker idles very bad when cold, yorker landau, miss fire

Question
I have a 1988 New Yorker Landau with 3.0 liter engine. I have had this problem for about 6 months now and have had it at my mechanic for this problem. When you start the car when cold, it has a very bad idle and seems like it is firing on 3 cylinders. I have to rev up the engine and wait about 5 minutes before the car is warm and then its fine. Runs great after that. It always starts right away, but again very bad idle and can not drive it until its very warm. My mechanic has given it a tune up, told me they can not find the trouble and has installed various parts to no avail.  Please help. My thought is its not getting enough air when started until a switch, who knows what switch, opens up when hot. It doesn't smell like gas when trying to warm up. I have also heard a popping occasionally when trying to rev it up to get warm, like a miss fire. The mechanic put in a distributor and cap. One of many parts that havent worked. Please help me.
Thank you so much.
Michael Klein

Answer
check coolent temp sensor,vacume to perge selonid,ingnition
coil out-put,and timming !!if all that fails pull the valve covers and check for week valve springs ,or ck for bad egr.
valve.Or do what all tech's do,check manifold vacume and
min. air speed,>> that tells a good story.tm