I am trying to get my mill back up and running, Dry cutting programs to assure no lost steps etc.  It's a TAIG mil,, with 400oz steppers.  Should be ample power.  Rapids of 40IPM, and jogging everything is fine. I can go back and forth all 3 axis no issues.  run X 100x back and forth 1" with dial indicator and stops great.  BUT, when dry running a file, it uses flood coolant.  When prog starts, and coolant comes on, I mouse click to turn off and the X axis skips, for lack of better terminology.  Sometimes it'll go completely out of sync, other times it'll restart, with some missed steps.  I've tried different Kernal speeds and such.  Like I stated, Jog's are perfect.  40IPM,, accel is 5IPSPS.  Computer is a 2500mhz intel running XP.  No other progs running with Mach.   

I
m pulling my hair out here.

It sounds like noise from the pump motor or the relays switching the motor.

Thx,  I was tired, never even thught about unplugging pump, and testing controls without the 120v.  Ya  no errors there.  SO working on relocating the 120v relay away from motion board/stepper drives.