Hi guys, i'm new to this forum and would like some advice. i have an issue with my focus 1.6 TDCI 2005 (62000 miles). under acceleration from roughly 1500 rpm to 2100 rpm in 4th &5th in peticular, i have a judder almost like the engine is struggling to push the car forward. i find this unusual as the engine is on boost and should be pulling.... also to add that this never occured before the issues as listed below. previous to this problem injector 3 had to be reseated due to a black tar like substence leaking out under the injector. AND the dual mass fly wheel has recently been replaced along with the clutch also. the judder is nowhere near as prominant as before the DMF was replaced. i have a few ideas such as: the DMF is incorrectly fitted, dirt within cylinder 3 causing a slight misfire, another injector seal is failing, the fact that the transmition is now as tight as a drum and this is how the engine actually feels at that rpm or my driving style is to relaxed?