Air control Sensor problem or what?

[SUBURBAN GMC TRUCK]

Suburban GMC '96 Turbo Diesel

My suburban Stalls Intermittantly. Just as what Pat Brennan posted - It's been doing it very infrequently for about a year, not codes left, dealer couldn't find anything wrong. Just last week it was stalling daily, but now seems to have cleared up. Stalls at highway speeds, Stalls at stop lights. Sometimes will not start right back up, need to pull off to the side of the road and turn key off, then on a number of times before it starts. Once it starts it can be good for days or for few min.

Ive been trying to trace this problem with my truck for a long time now. Recently I have been leaning towards the ACS as being the problem. Could anyone give me their school of thoughts on this and how to replace or repare the ACS?

Much appr. Jon