The Grove-based squad failed to live up to expectations in the season opener as both Maldonado and team-mate Valtteri Bottas struggled for pace.
Maldonado said the warmer temperature at Sepang had improved matters for Williams, but he conceded his car is still not competitive enough to fight for a top-10 grid slot.
"It's a bit better now, but still difficult. It's completely different situations, different tracks, different conditions," said Maldonado after posting the 16th fastest time in second practice.
"It's quite difficult to understand all the problems that we have. It's difficult to find the solution. I think it's going to be a hard weekend for us, but we need to wait for the race. Anything can happen and we need to be ready for whatever happens.
"We improved the car a little bit. We will improve for qualifying tomorrow, but we are still far away from the target.
"Q3 is looking far way, and points we'll see. Anything can happen in the race. We need to be consistent and try to get 100 per cent out of what we have."
The Williams driver claimed his team understood what was wrong with the FW35, but admitted it was proving very hard to find solutions.
"We know what is happening with the car. We don't know how to solve the problems. We tried different things. We improved a little bit, but there is still a lot to do."