Car is at the dealer... Replaced all spark plugs and coils and injector for cylinder 3 (had misfire code) 02's pre cat both were replaced and HPFP under warranty and still car shutters under acceleration between 1500-2200 rpms.... Does anyone know what I should be looking at before I start throwing on more parts

 

How many miles?

Have you had the intakes walnut blasted? Carbon buildup on the intake valves (common problem with the N54) can cause the shuttering you describe. My dealer covered the walnut blasting under goodwill at around 85k.

 

Sorry I forgot to mention walnut blasting was just done and there was so much buildup but still didn't solve the problem

 

Were the plugs/coils/injectors replaced at the dealer? Plugs should be Bosch ZGR6STE2 (pre-gapped), Bosch coils, index 12 injectors. Was the new injector coded properly?

Is the car throwing any codes?

 

Everything was replaced by the dealer.... No codes are being thrown they're as stumped as I am

 

Did they only replace Cyl 3 fuel injector? If yes, replace all 6. My car had similar symptoms and replacing the injectors solved the problem. These injectors could be covered under BMWs emission warranty, so look into that.

 

Yes all injectors were replaced... I just got the car back the acceleration and power is much better almost night and day difference... Unfortunately the car still shutters and pretty badly when on an incline (hill) but on flat ground it's barely there

 

I'm having a similar issue. The dealer is currently replacing injectors under warranty... I'll get it back Monday and find out if that fixed it. Coil packs and plugs were replaced too.
I guess I should do a walnut blast too??

 

Yeah the walnut but blast makes a huge difference I mean night and day... Well for me it did because my valves were badly gunked up.. Today I removed the vanos sensors and cleaned them... Noticed the stutter was not as bad at all... Might consider replacing both of them and see how that goes...