Order Analysis

[rladr]

Yes, Keyphasor is on the same card.

[preston_johnson]

are you resetting all the VIs?  Resampling, Tachometer, Mag and Phase?

[rladr]

Yes, all three

[preston_johnson]

when you view the time waveforms, is the phase obvious and stable?  Can you share a picture of your block diagram? 

Do you have a non-zero value for triggering the speed signal.