I had a 91 chevy lumina that did the same thing, randomly die while driving. I replaced everything from the ecm to the coil packs. After $695 worth of new parts, it turned out to be a $13 knock sensor. I don't know if it is the same issue with the suburbans or not but my 2002 burban is doing the same thing now. I found this video on youtube showing replacement procedures. I'm going to give it a try. I will let you know.