I have a MGL EMS Extreme engine monitor which cannot record GPS data. However, I use ForeFlight to record my flight's GPS flight path. Is there a way to merge the GPS data into the 'Flight Data Viewer File'?
Yes.
You will need to download a utility to perform this task. The download and usage instructions are in the links below.
Download and install the flight data / KML (GPS) data merge utility
How to use the flight data/KML (GPS) data merge utility