Camshaft or Timing Issue?

[Seagates]

I have a 03 325ci thats been acting weird. I got a SES light P0340 for the exhaust camshaft (BMW fault code 18). I replaced the sensor with another bmw sensor and still the code came back. Rebuilt the VANOS unit which made the car start and runs better but its still stumbling and the idle is still surging a bit and there still a major loss of power when driving. I double checked the connector and it has the 12v for power and 5v for the signal wires. Im not sure whats still causing the issue. Would it be that maybe the timing is off or would the crank sensor be bad? Theres no issues with startup but it will stall if you dont hold the rpms until its warmed up. Anyone have any ideas or suggestions?

[Muzz258]

Sounds like you have an air leak. Look for breaks in the hoses between the MAF and Idle control valve/throttle body. The small tube that feeds the idle control valve is the usual suspect.

[Seagates]

Checked hoses and they're in good shape. Also I checked short and long fuel trims and they also show no signs of air leaks

[Seagates]

Checked hoses and they're in good shape. Also I checked short and long fuel trims and they also show no signs of air leaks

[90turbo1]

i would still suspect a vacuum leak. it can leak from anywhere. if you had a timing issue that was enought to make the motor run like that you would have corralation faults between crank and cam sensors.

I wana say there was a bulletin for surging and we programmed them along time back. but start with your basics. what is fuel pressure, has fuel filter been changed (they are very fussy with fuel issues). all and i mean all intake areas and v/c gaskets in good shape. what is ccv doing? compression check? ignition system in good standing.

that fact that you have a constant exhaust cam sensor fault is suspecious though.

[Driiven]

use an oscilloscope to check timing and its the signals feeding the ecu. two birds one stone