Keep going, using computers in project (5,2,3)
I believe the answer is:
stick it out
'keep going' is the definition.
'computers in project' is the wordplay.
'computers' becomes 'it' (information technology).
'in' means one lot of letters goes inside another.
'project' becomes 'stickout' ('stick out' can be a synonym of 'project'**).
'it' going within 'stickout' is 'STICK IT OUT'.
'using' is the link.
(Other definitions for stick it out that I've seen before include "Persevere to the end" , "Persist" , "Don't give up" .)