Im having accelorator problems in high gear. I have a 5 speed and with the pedal to the floor on highway im maxing at 3000 rpm (speedometer is broken..guessing 75-80 mph). When hit incline power decreases and have to downshift to forth not to slow down. I thought carpet at first bloking pedal but cleared that up. Is there something in the pedal box or pedal mechanism that could be causing this? Thx in advance