hi all newbie with gsr problem

[rodney]

hi all just purchased a baleno gsr and have a little problem. when i put my foot down the car kinda stops revving between 4000 and 5000 rpm then piks up and goes like a bat out of hell. any help would be appreciated 

[GSRLoz]

got any fuel? haha, you using much oil? mine does this occasionally, but since i changed the plugs for the proper iridium ones and added a few extra earths it seems to be okay