Furnace Tries 2 or 3 times before staying on until reaching set temperature
Well, I know this post is old but a simple way to test your pressure switch is to turn off your furnace first and close the gas valve for safety, then gently unhook the air tubing from your draft inducer and gently suck on it using just the suction your mouth creates, I wouldn't inhale it, you should hear the pressure switch click and feel a restriction while sucking on it.  If you do not hear a click, can keep pulling air, or cannot pull any air at all your pressure switch is probably bad.  If your pressure switch tests good, then try cleaning out the inducer connector it could have junk in it.  If it does have junk in it, it may be a good idea to change it out because it is probably rust.  That is what was wrong with mine.  I had a faulty pressure switch and s rusted out inducer fan.  The inducer motor itself ran fine.  After changing out the pressure switch it still would not fire up.  So i pulled off inducer motor and the fan was completely rusted out.