Extruder 100mm Very Slow

[JamieLee2k]

I have just updated to the latest firmware after installing a few new things like Micro Swiss Hot End and a Redrex All Metal extruder and so when I heat the nozzle and try to extrude 100mm it comes out slowly and also its more like 66mm, now normally I would just adjust it but on the last firmware (may) I had the same issue at first, when it came out slow it was always shorter and when I turned it off and on it would go fast then extrude close to 100mm, since I have a new extruder I will need to redo it and this is where my problem is.

Is this my fault because I am 100% sure I have installed everything correctly, I have watched multiple videos to double check and it seems I have done it.