I'm having two new issues in this cold weather. The truck isn't idling well during a cold start, idle drops down to 400 rpm and stall sometimes. I usually have to open the throttle to prevent it from stalling. After driving it and warming it up this isn't an issue. I read somewhere that a vacuum leak could cause this, but I thought a vacuum leak would make it idle higher not lower? The other issue I noticed is there is no brake booster power when its cold, the pedal is rock hard. Again, after it warms up the pedal is softer. Any suggestions?