Bit of a puzzling one.
Ok, the intake vaccum solenoid - I assume this is the turbocharger boost control solenoid? It has a vacuum line that goes to the round gold part on the turbocharger? If so, this is a common failure point but it shouldn't shut the car down. It will just make it blow black smoke and perform really poorly.
The only other thing that's controlled by vacuum is the brake booster (and that does NOT go through the solenoid, it's a direct connection from the vacuum pump to the booster).
You may still have some of the original problem here. Try this: remove the screw near the ECU that goes into the bodywork (this is the ECU ground screw). Clean up the metal surface, reconnect the ground and do the screw up tight, test the ECU comes on (can you start the car?) then spray the connection with battery terminal sealer or any good paint (if using paint, consider 2 or 3 coats).
If the BCS still doesn't function properly, you can either get a replacement (about AUD$40 from eBay, AUD$250 from Nissan) or change to a Dawes or Tillix valve which controls the turbo without any input from the ECU.
