Weird OMP problem
 

well about a week ago i put in a different OMP and lines in my 88 GXL, since the ones on it were melted. now when i drive, after the car warms up to operating temp the OMP lever is hard to move and it makes the gas pedal really stiff, and it will stick up, then when the car cools down it moves easily. can anyone tell me why it does this??

thanks

anyone??