I have a 1990 Lincoln Town Car with the 5.0 that has about 153000 miles on it. A couple of years ago the car was surging and dieing while driving it, i took it to a shop and they fixed it,it was a vacuum leek under the upper plenum that went to the map sensor. The next summer it started doing it again so i took it to a different shop and all he did was get into the ecm and mess around,averaging certain things if im not mistaken like the tps and map sensors,i dont know nothing about that stuff its just what he told me i think,anyway over the winter i ran somewhat better getting 10mpg c&h but the car never got up hot enough for the heater to work and the gas gauge goes crazy now up and down all the time and it started surging again,so i took off the upper manifold found out it didnt have a gasket and the map sensor was capped off so i put on a new gasket and ran the vacuum line to a new map sensor,and it runs great now(15mpg city) except it revvs up high on start up and idle back ok and it dies at stop signs.ive tested the voltage at the tps i was getting the correct readings before i took it to the shop now im not its reading 5.25 with the throttle closed,and the new map is reading 2.89 constant it dont matter if you vacuum pump it or not,the one that i took off a motorcraft reads 2.75. so stupid me i have my wife run it down to same shop as last time for the dieing at stop signs he said it your map sensor but adjusted the tps i think cause now it wants to pull a little while stopped with the brake on,but know i have three maps that all read the same or close to reading 2.89 & all but one is new.the service engine light tends to go off while driving till you idle down then it comes back on.whats going on??and also the gas gauge never acted like this till i took it there.i hope this made since cause it dont for me no more.so basically what happened i think was the first shop capped the map off,the second one did something in the ecm,then i fixed the real problem and then the second shop fixed the tps and tried to get her for $200 to put on a new map and that included the diagnosis ,she left only paying $90,i went and got a map but all three read the same??