Making first and fourth characters run very fast in error (8)
I believe the answer is:
misprint
'very fast in error' is the definition.
'misprint' can be an answer for 'error' (misprint is a kind of error). I am not sure about the 'very fast in' bit.
'making first and fourth characters run' is the wordplay.
'making first' becomes 'm' (ist letter of 'making').
'and' says to put letters next to each other.
'fourth characters' becomes 'i' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'run' becomes 'sprint' (sprint is a kind of run).
'm'+'i'+'sprint'='MISPRINT'
Can you help me to learn more?
(Other definitions for misprint that I've seen before include "mistake" , "could make sinners of the winners!" , "Typo" , "bad spell perhaps" , "Type of slip" .)