i used to have the same problem and heres what i think you should do that helped me out a lot...
if you arent already...leave a separate day for Arms (biceps, triceps) this will make sure they are being worked first and this will help to strengthen both..
also, go nice and slow, especially on curls...make sure its a controlled motion
changed your rep range...and the order of your exercises
last but not least....superset biceps and triceps...this will give you a great pump that im sure will help you
best of luck