91 240 engine surge without pressing gas

[e777]

Hello,

My wife was driving her 240 wagon (236K miles) today and swears that as she was sitting still with the car in drive and with the brake on, that the engine surged without pressing the accelerator. There was enough of a lurch forward that she needed to apply the brake to keep the car from moving. I have not been able to replicate her experience. I tried to research this on the internet and did not find what I was looking for. Very strange.

Any input would be appreciated!