To answer your question Jesus was without sin until his death when he took on the sin of the world, where he then defeated death and rose again. Many use the temptation of Jesus to label him as a sinner but we are all tempted, the temptation itself is not sin, giving in to that sin is. Jesus is neither God nor man, he is a split being he is man but his tendancy's are God, in a sense hes God with limits (but these limits can be changed and altered as he sees fit). We see evidence of this split when Jesus cries out on the cross "My God, My God why have you forsaken me?" Jesus is looking for the God part of himself and finds that God and his other half has turned away in pain. The concept is difficult yes.
If Jesus did not sin then you seem to be denying that he was fully human remeber "all have sinned and come short of the glory of god".
If the god part left before the death then god did not die for you.