My 01 GP sputters and jerks when you get on the gas or go up a hill. It seems to run good when going down the road at a steady speed but when you need more power is when it acts up! It had a total tune up not long ago and also a new fuel filter. My mechanic wants to put a new fuel pump in but want to get a 2nd opinion before I shell out 300 big ones. Has anyone else had a problem like this?