My daughter has a '94 850 sedan with about 90K on the clock. She had the occassion to stop hard enough recently to engage the ABS and thought there might be a problem saying it rumbled when she stopped. I told her that was normal, but the next time she brought it to me, I'd check it out. Today, I got it up to about 30 mph and stopped and engaged the ABS. They worked perfectly. But, when I went to step on the gas after I came to a stop, there was a 1 1/2 to 2 second delay before the transmission engaged and I was able to drive on. I recently flushed the trans fluid and it was at the correct level today. It shift normally otherwise. What could this lag after stopping after engaging the ABS?

Thanks in advance.