My ‘86 had a similar problem, see post #6 in this thread,
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Your EGR valve may be different than mine, my Tempo has the early fuel injection.

1987 Ford Tempo
My 1987 Ford Tempo GL Coupe runs great at 169K original miles. But it has developed a bad habit that has stumped two different Mechanics and cost me over $1,000. so far, to fix. Which by the way, no one can figure out what is going on. The problem is that it doesnt idle, and quits going...
Your EGR valve may be different than mine, my Tempo has the early fuel injection.