I have a 1988 mustang gt. I have been experiencing a problem for close to a year. My car works fine when driven around town. When I get on the interstate, or when I drive it at a constant speed for about 30 to 50 miles, it starts sputtering really bad and eventually dies. If I let it sit for about 30 min or so, it runs fine. Since the start of this problem I have replaced the fuel pump, filter, ignition module, coil, and map scensor with all new parts. I am still having this problem. When the problem happens I have tried different little things. I notice when this happens I can unplug the map scensor and the throttle response is strong at first but eventually gets weak. With it not unplugged though, and the problem first happens, the car will not even crank up. Any ideas?????????? Email me at chad5444@aim.com. Thanks