my sable has 93000 mi on it owntoplied it 2 weeks it runsd veryhot,idlesbadstopd on 1990 Mercury Sable

uses excessive fuel,(like 15 mpg!)
) from a strongly running engine otherwise.... whenbraked at stoplights she shudders surges in place of idling.
oh and she often needs coaxing when restarting if warm.
also displays rough idle on cold start thar soon smooths out. but often needs throttle pressure to accomplish smooth out

Asked by for the 1990 Mercury Sable
Fuel pressure , injector(s)/regulator leak-down. TEST first.Fouled plugs. Lack of maintenance.
1 more answer
anybody out there feeling "map" sensor? or brain entirely? 15mpg at 93000 miles?
shifts slow breefeet?