Imhotep can change his form into a sandstorm which allows him to emaciate a human fully within seconds, or he can control the sands of a desert. He can send winged insects (wasps?) from his mouth. We saw some telekinesis in the sequel. He can reattach missing limbs. He does't seem vulnerable to conventional weapoons. His only weakness is that book that stole his immortal soul and whatever stopped him in the sequel. He also has superstrength. I am assuming that he is at full strength and therefore doesn't need to absorb any more life energy, although I think he can still steal it.
Dracula can change his form into a pure wolf, a werewolf, werebat, mist, and into a young version of himself. He has fangs, strength, stick to walls, and can control wolves. He is resistant to pain. His weaknesses are sunlight, which weakens him to about half his power (remember this is not the convention definition of a vampire), crosses which repel him, decpitation, and he can only sleep on his native soil. He was killed at the end of the movie/book by being stabbed at dawn before he could reach his native soil.
The fight will be at night so that Dracula is at full strength. Dracula can't suck blood from Imhotep's undead body and Imhotep can't get life energy from Dracula. Imhotep's sandstorm won't work on Dracula's mist form. So it comes down to hand to hand. Dracula's wolf form could take Imhotep apart. That won't stop him unless Dracula takes all his limbs and then scatters them. This would stop him from fighting back, a TKO. The book doesn't exist in my arena therefore Imhotep can't be killed. This is the best Dracula can do. Imhotep could only beat Dracula around a little, but not fast enough to stop the wolf attack proposed.
Winner: Dracula