The Reds beat Tottenham in last season's final but lost all three away group games and in Napoli this season.
They play Genk in Belgium on Wednesday.
"Last year we were lucky with how tight the group was that we could lose three times away and still have a chance to make it through the group," said Klopp.
"That will not happen this year. It's completely different.
"We know it's not historically good what we have done (in the away group games) in the last few years, but in general the Champions League was obviously really good.
"We did the right things in the right moment but we don't rely on these things. We know we have to improve and we try again and again and again until it works out."