How can a VANOS solenoid go bad just because the car had been sitting for a year ? Sure the oil could of drained out of it, but a few miles of hard driving would soon fix that. The ICV controls the idle speed not the VANOS.What solenoids did you install, & did you reset the adaptations on the engine. This will make a ig difference. What ever your problem is, it is part of the Vanos system sensors. Disconnecting the MAF & running better, verifies this.
IF like OP states the engine is fine after idle and drives well, then VANOS is functioning.
Alot of water tends to accumulate in cold engines when the heat is not there to evaporate it all out the tail pipe. Disconnecting MAF just proves the issue is with fuel trims as a fixed default fuel map is then used.