I'll wager when you compare the weight difference between the old and newer escort, you will find the culprit. I did have a bookmark showing weights of different year escorts but I'm not sure where it went. I want to say there was at least 100# different.
Often, as carbed engines age, their a/f will start going leaner (vacuum leaks will cause this often). A carb cannot compensate for a vacuum leak, while FI can and often does compensate.
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