my injecters seem like they are blocked as in high gears on low revs my astra sxi is hesitant and juddering. could this be a blockage or a faulty air flow. i've heard somewhere before that the mark 4 astra's have a problem with the oil going hard on cooling causing blokages too.. does anyone have any idea's how to solve this problem. also what materials would i need to solve.. ta..

James, June 2009