Troubleshooting a Viper Fog Machine

Hello Cube, We are running a show in Bushwick, Brooklyn that utilizes Viper fog machines. Currently the units are experiencing intermitent and unwanted bursts of fog that don't fall in line with the cues. We have tried everything within our knowledge with the unit and the DMX run to it. We could use any advice or support on site tomorrow between 1pm and 4pm