Do you have the AAMC Question Packs? I'd run through those and work on timing there.
On my first practice test (PR) I paced perfectly for C/P. Fine on a second. On the AAMC practice a week before the exam I didn't answer 7 questions because I ran out of time. After revisiting pacing strategy (introspective, looking at the AAMC practice test and Q-pack) I saw that I was mainly getting bogged down on Chem passages that I simply didn't know the answer for. Instead of making an semi-educated guess (knock out 2, then flip a coin?), I was trying to reason out the answer and spending >3 minutes on random questions instead of marking them and returning. Soo... I studied my weak chem topics.
On test day I wrote at the top of my paper in big letters/numbers: "59 Q, 95 Min. 30Q, 47 Min" and circled it. Just to remind myself to look at the half way (time) to make sure I was on track. You can be responsive in the test, and if at the half way (time or question number) you find you're going too slow or too fast, you still have time to modify your behavior.
Spending 3 minutes on a question (to get it correct!) is ok if you only spend 20 seconds on another. I didn't limit myself on any particular passage/question, but I kept the 'checkpoint' in mind to assure I wasn't behind.