Squeak in 97 FJ 80 - Ideas?

[mfw757]

My 1997 FJ 80 has 67,000 miles and when accelerating from a stop there is a rather high pitched squeaky sound for a couple of seconds. It never makes the sound at any other time (stopping, accelerating at a speed greater than 10 miles per hour, etc.). It does not make the sound everytime I accelerate from a stop. The sound is not made if I hold my foot on the brake and depress the accelerator. Any ideas what this sound may be? Thanks in advance for your suggestions.

Mark Walz
Houston, Tx