I always play along to a metronome and My timing is very good.
The problems occur when there is no metronome. Like sometimes I play in a acoustic duo and I always start the song too fast and get faster towards the end. I think its because I get too excited maybe?
How can I stop this?
I sometimes listen to the tempo on the metronome before I start but I can't always do this, anyway towards the end I lose it and get faster.
Always tap your foot along with the metronome and then when the metronome isn't there hopefully you will still tap your foot.

Great tip, I never thought of this!
I have a similar issue with rushing the tempo as I go along when I'm by myself. This is why I really respect drummers with solid internal tempo. Tapping my foot is helpful but even then it can still fluctuate if I'm not careful. Part of the battle is just being aware of what's happening as you're playing. If I can feel myself rushing I can relax a bit and focus on getting back to the right tempo.
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I agree with V3n0m777! The absolute best way is to tap your foot along with the metronome/drum machine/backing track that you're playing with. So, when it's absent, you'll still tap your foot and keep beat.
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