86 ford mustang pls help!

i have an 86 ford mustang its not a 5.0 somone told me its a striaght 4 anyways i can drive in reverse but when i put it in gear to go forward its like its still in nutral and doesnt realy go anywere plus it cant even make it up a hill with a 10 degress incline whats wrong?:sarcasm1: pls help