I noticed my 00gt was considerbly slower when I ran the AC and/or when it was hot out. It never ran the same as the nice cool nights or mornings as it did when it was 75 and sunny. Just an fyi, probably not it, but some people forget that.
And my .02 about fuel pumps, when mine was going out, the only time it worked correctly was under full throttle, I.E. hard acceleration, it continued to get worse if I daily drove it normal, but would still be fine if floored, make sense?