J-head extruder not reaching temperature

[Gbendtsen92]

I designed an adapter bracket to hold a J-Head extruder on to my rostock max v2 as well as a new cooling fan for the heat sink portion of the extruder. When I run the pid auto tune program it can get to temperature without issue and gives me the values to plug into the appropriate fields in the eeprom which I have done. The problem is when I try to print a part the extruder is only getting to 221 when it should get to 228 for abs. In order to circumvent this issue for the time being I have been setting the extruder to heat to 235 and it ends up getting to 228 so it will at least start printing at which point it drops back to 217. I would like to use nylon filament soon and in order to do so I will need at least 240c so with 240 being the max setting you can see my problem.

[Polygonhell]

It's the pid values, autotune does a crappy job.
Increase P or decrease I and D manually.
I always end up manually tweaking mine.