[e28bmw]

Hi guys, my N54 has started misfiring badly on idle and shutting down cylinders 2 and 5. I have swapped out the plugs (gapped accordingly - NGK) with no difference. I have swapped coils from the problem cylinders and the fault does not follow. I have removed and cleaned the vanos solenoids and injectors and still made no difference. I have pre cat lambda sensors to replace but get no lambda faults (figured they would be due soon anyway as on 106,000). I've been running logs from my JB4 and trying to interpret them and don't believe there is a fuel pump issue (lpfp - constant 65/67 psi on idle and hpfp - constant 750 psi on idle).
I'm not really sure where to go from here without just throwing money at it.
Any suggestions on things to test or look for in logs? Can I test injectors without swapping them to different cylinders and recoding?
I did have oil on my plug threads and injectors so I know my vcg or VC is gone too and have a new gasket.

[Phil325i]

As you say, so many possible causes. But the presence of oiled plugs would be my first target. Suggest you get your VC and VCG issues sorted, clean up the plugs and try again.

Failing that, I'd probably use an Indy with access to the latest BMW diagnostic software, otherwise your car's in danger of turning into a money pit of replacing parts and hoping...

[e28bmw]

Originally Posted by Phil325i

As you say, so many possible causes. But the presence of oiled plugs would be my first target. Suggest you get your VC and VCG issues sorted, clean up the plugs and try again.

Failing that, I'd probably use an Indy with access to the latest BMW diagnostic software, otherwise your car's in danger of turning into a money pit of replacing parts and hoping...

thanks Phil. I'm going to get the lambda sensors done this afternoon and the vcg tomorrow and inspect the cover and go from there.