Posted this on the R56 talk forum too.

Removed the intake and performed the walnut shell blasting of the intake valves yesterday. Put everything back together today and added the BSH oil vapor can.
Car will turn over but not start.

Made sure pistons were at top of cylinder before blasting . Initially used the starter to turn the engine over but it is to difficult to ensure the valves are closed. Auto so I couldn't roll the car. Turned the crank bolt CW with a dowel inserted in the spark plug hole to ensure the piston was all the way up. Also checked with air.

Cleaned valve pairs and then sprayed with carb cleaner, soaked 10 minutes and removed dirty fluid.

Re-assembled today, removed PCV pipe and added the 2 PCV plugs.
Installed BSH oil can and hoses.

Cleaned the throttle body, opened the butterfly valve and wiped it out

Installed new plugs.

Some rust on the coil packs so I cleaned then with steel wool, wiped them down and put some WD-40 on the metal.

After no start issue I removed the coils and cleaned the WD off with brake cleaner.

Engine would turn over but not start, got a warning of engine malfunction.

Pretty sure I connected everything back up.

removed - bat terminal and let sit for 10 minutes, attached but didn't make a difference, did this a few times. Still would not fire. Battery was running down so I pulled it and have it charging.

removed a plug and it wasn't wet. Fuel issue?

Filled the car with fuel Saturday as I was pretty low, drove the car 90 miles that day.

Any thoughs, where to go from here and what to look for?
Thanks, Glenn

 

Some have mentioned in other posts they too had issues getting it started. Assuming you don't have anything in your combustion chambers, it may take several trys to start. I believe I say somewhere where it took around 20 trys to get the car started again.

 

After having mine blasted, itstarted and ran very nicely until I put it on the track and couldn't get it to produce much boost. Although not the same issues you report, check the hose between the air intake the map sensor and the turbo. I found the hose clamps completely loose. In my case the MAP sensor didn't like what it was seeing. After insuring all connections were tight and secure, it took several days for the issue to resolve itself. I was told the ECU had to resolve the issues it found. Could it be something along these lines? BTW, it never threw a code.

 

I took everything apart again this morning to verify the connections but it still didn't start (much faster the second time).
Put my battery jump box on and it almost fired.
Have the battery and jump box charging now.
Maybe the battery is going and it isn't turning the car over fast enough?
Pulled a plug and it still wasn't wet.

Stumped for now!
Thanks,
Glenn

 

You probably got some walnut media in the combustion chambers and it's fouling your atomized fuel. It happens when you walnut clean an intake port with a valve open. Once you are powered up, I bet it'll start reluctantly.

 

It was suggested that it may take 20 times before the car would start.

I charged the battery and had it checked at Autozone, was fine.

Tried the start/stop and after numerous times it finally started!!!

Appreciate all of the help!!

Glenn