I go in upfront, but with no success (2,4)
I believe the answer is:
in vain
'upfront but with no success' is the definition.
I can't judge whether this defines the answer.
'i go in' is the wordplay.
I cannot really understand how this works, but
'i' could be 'a' and 'a' is located in the answer.
'in' is found in the answer.
The remaining letters 'vin' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for in vain that I've seen before include "Without effect" , "Futile" , "Without success or result" , "Uselessly, to no avail" , "Uselessly, to no profit" .)