BMW Repair: hesitation, 1989 bmw 535i, bmw 535i

Question
1989 BMW 535i
vehicle under heavier acceleration hesitates and jerks when rpm reaches 3000 ot 3500 rpm.  Under moderate acceleration vehicle speeds up fine.

Answer
dear
acc. proplems allowes caused by the fuel injection system then check the injector and the time of injection and spark timing i think it is not easy with out using star diagnosis so that you have to go to work shop and check this things

hope to be right in my opinion