I have a 1989 Nissan 240sx with around 35k miles on the motor. Off the line it stumbles unless i give it a good amount of gas. Also, whenever it'sbetween 2500-3500 rpm it hesitates and it doesnt 'go' like it should. I'm going to buy a new mass airflow sensor, wether it be from another car since its cheaper, or a new one. Does anyone know what else it might be?