[ac1999]

Hi All,

Car has 110k miles on it (2011 335ix w/ N55). It has been in storage for several years. The previous owner put it in storage after not being able to figure out this exact problem. When we bought the car it would start and idle VERY rough. The car will still crank. It will sometimes cough a bit and try to run, but it never catches.

Codes:
3429 - oil pressure too high before engine start
29D0 - intake air temp sensor short to B+
2DD8 - valvetronic position sensor
2BF8 - rail pressure sensor permanently stuck
277A - hot film air mass electrical fault
2C72 - boost charge sensor pressure too low
387F - power management, standby current violation
6EC4 - DSC - steering wheel sensor adjustment
54C6 - VTG - Oil wear
A387 - TCU fault Bluetooth

The intake is off, and we replaced the Valvetronic motor but are unable to calibrate it because the car won't start. Those two conditions account for a few of the faults.

When we got it there were misfire faults in several of the cylinders. That lead us to replace the injectors, which cleared up those faults.

There is no spark on cylinders 2 and 4. Verified visually by removing the plug and with a test light on the wiring harness, for both cylinders. Both have good 12V and ground. Both coils and plugs work in different cylinders. We have also verified wiring continuity with a DMM.

There seems to be plenty of fuel coming through the rails, verified by removing spark plugs and loosening the rail fittings.

To summarize, we've done the following:
1. Replaced the battery.
2. Replaced (and coded) all injectors, plugs, and coils.
3. Replaced valvetronic motor (there were some other valvetronic faults that cleared up once we did this).
4. Verified continuity with a DMM in the spark/injector wiring harness from all pins to DME.
5. Sent DME/CAS/key to ECU Pros to be verified - it came back with no fault and a video of it running in their test vehicle.
6. Cleared all faults with ISTA+. They show back up after cranking.

The only other thing I can think of at this point that would affect spark in individual cylinders is the crank position sensor and/or reluctor wheel. Seems improbable though since there are no faults.

What am I missing?

[ac1999]

Resolution.

VANOS solenoid was bad. We replaced that and the engine would start reliably, but sill showed misfires on 2 and 4.

The coil 2 and 4 receptacle contacts on the female side of the ignition wiring harness at the DME were just lose enough that they would not make solid contact with the pins on the DME. Checking continuity showed the harness as good, since we were making sure to have good contact on both sides of the harness. When plugged in, the contact was not being made.

Replaced the wiring harness and the engine fired up like new.