I am getting a P0204 code on #4 cylinder on my 2003 R50. I have replaced the injector & camshaft position sensor. The injector sounds like it is working, but the engine starts to miss within a minute of starting the car. The service engine light will eventually start flashing and it will run like it is on 3 cylinders. If you shut the car off and restart it will run smooth again until the problem re-occurs. Any thoughts on where else to check?

 

first, check connections for bent pins, corrosion, etc.

Do you have 12v with key on engine off at the connector?
if yes, then check for shorted injector ground circuit by removing the DME connectors and put your ohmmeter on the ground side circuit of the injector harness and engine ground.

if ground path shows "OL", then ohm check pin 22 at the DME to the end of the #3 injector.

IF "OL" then you have an open circuit from DME to injector

IF ~0 ohms then you have a faulty DME (signal not operating).

if no power, then follow power path up the common 20a fuse that powers all 4 injectors (F02).

 

Thanks!!! I will check these out and let you know!

 

Any luck solving this?
I have 2003 Cooper S and #2 injector giving me the same symptoms!

 

No luck. The car has been at a mechanic for over three weeks and it looks like the only thing left is the ecu. I am shopping for a used one with the bci and key for a swap.