Car intermittently dies until warmed up

[wickerwagon]

I have an 89 Plymouth Sundance Turbo which I purchased new in 1989. I have been the only owner and put 225 k miles on it. Recently, it started on occasion dying when first starting up. It does not always do this but it can happen when cold or when driven for a few miles than stopped like at a grocery store, then started up again. It is not consistent. It runs great except for this little problem on occasion. We have changed the spark plugs, oil, oil filter, air filter, radiator fluid,and fuel filter in the last week. It has helped but it still, on occasion does not keepgoing without adding extra gas when first started. After driving a blockor so, it keeps going. What should we be doing besides running it over a cliff??? Thanks