Is there a way to automate the timing on midi drums that were played externally on a electronic drum set...for instance if the timing might not be right the entire time?  

Quantizing?

^^ It's called "quantizing", but be careful, the results are rarely what you expect. Better to manually fix a few obviously out-of-place hits and trust the drummer for the rest.

Only if they played to a click track. 
 
What I do is look at how they line up to various grids you can set the view in PRV.
So ,say they are very close to a 16th grid I will quantize to that. And I do each drum part individually. 
Like the kick is normally only a 1/8 note quantize but the hi hat might be 1/16ths and even 16 triplets if its a shuffle. 
The snare I almost always manually edit because there is so many variations with rolls. 

As other have mentioned, quantise would be the way to go.  However, you don't want to apply 100 percent quantise. 

Leaving some of those little timing errors actually makes a rhythm section (or any section for that matter) come alive.....

promidi
As other have mentioned, quantise would be the way to go.  However, you don't want to apply 100 percent quantise. 

Leaving some of those little timing errors actually makes a rhythm section (or any section for that matter) come alive.....

depends on the genre.  I record synthpop and i like my parts tight and precise.  that only works for synth music though.

That's why you sort of have to use quantize with musical knowledge in mind. You need to listen! 

If the problem is inconsistent tempo, as opposed to the drummer obviously screwing up specific hits, then it's probably better to match the timeline to the performance rather than the other way around.

AdamGrossmanLG
 
I record synthpop and i like my parts tight and precise.  that only works for synth music though.

And metal too.

If the drummer played to a click, then quantize and possibly a little bit of surgery on individual hits should get you where you need to go. If the drummer didn't play to a click and did something like play at 108bpm while sonar was recording at 120bpm then... oye. Its probably going to be tough to get that to line up to anything.