I have a problem running The GPS Pmod and the ESP8266 Wi-Fi module together !! whenever the Wifi module is activated the GPS stops working trying to connect the GPS with the arduino alone works normally !! The problem is when the Wifi module is added !! Any help ?!
They are using the same interface？And the power supply, what is your adapter or usb from pc？
The WiFi unit may be emitting frequencies that are in the GPS band, if that is the case the GPS will not be able to find satellites. Test running the WiFi unit inside say a coffee can with tin foil covering the hole, if you do that watch out for shorts as the can is a conductor as is the tin foil. The GPS unit stays on the outside. You will have created a Faraday cage with the foil and can which will dramatically reduce the radiation emitted by the WiFi unit. The problem is the out of band emissions from the WiFi unit of the GOS works when the WiFi unit is in the "can".