Im trying to understand what pulseing mean?

 

Asuming your talking about the engine....

as a rotor completes 1 full rotation inside it's housing...

the seals will pass over the exit port 3 times (because there is 3 sides to a triangular rotor)...

each time it does this, a compression sound or "pulse" can be heard...

unless there is a problem with the seals sealing against the housing...

thus resulting in low or no compression sound or pulse....

so if the motor is good people have be known to say "it has 3 strong/good pulses"

hope that helps.
Cam...

 

I couldn't have said it better myself.

 

Great explanation - the concept can be expanded to the dynamics of the exhaust with a running engine. Hence Racing Beats exaust name Power Pulse......