LOSS OF POWER?

LIKE MANY OTHERS I HAVE LITTLE POWER UNTIL ABOUT2300 REV WHEN TURBO KICKS IN. WOULD A FAULTY CRANK SENSOR DO THIS, OR WOULD IT ONLY AFFECT STARTING AND CUTTING OUT PROBLEMS, AS MINE STARTS OK AND DOES NOT CUT OUT. VERY EMBARRASING PULLING AWAY FROM LIGHTS OR GOING UP A LITTLE INCLINE.