Do you get any computer codes or Service engine light on? If not or the one you get is only 44 for a lean exhaust condition check for vacuum leaks. Recently spent three weeks with my 88 LE ; thought the problem was the MAF sensor, but later found the MAF would usually give a code if it went bad. Found the leak by spraying carb cleaner around places that could leak and as soon as we sprayed around the intake the engine speed would increase. Took the intake off and it was very obvious where the leak was as a section of the gasket was blown apart.