V6 Vortec idles cold

I have a 94 GMC Safari with the W engine that never seems to warm up too operating temp during idle. My main concern is in the winter when prewarming it with my remote start. I have replaced the thermostat, O2 sensor, plugs ....the injector assembly that is on the inside of the intake (forget what its called) It starts and runs good gets the factory rated MPG actually 1 MPG better. My conclusion is that the idle mixture is set to too cold of a burn. The exhaust smells rich....not like raw gas more like an old 60's non computer car Can the eeprom be replaced to make a hotter idle burn. I have a eeprom burner and just need the file to copy it to a chip. Or is there program to read and edit the existing chip? If I turn on the front and rear heaters they remove enough heat that the t stat never opens during idle.