just as a follow-up to my issue... i checked to see if the hose going to the sending unit was under vacuum upon starting the car and it was, ruling out any issues there. also tried putting a new piece of hose on the sending unit and blowing/sucking air into it to see if it registered any boost/vacuum and it didn't, which meant the unit itself was broken. i sent it back to andy and he fixed and returned it to me within about a week. AWESOME!