have a 1991 chevrolet silverado 1500 dies at all stop signs..otherwise runs good have to crank it back up though every time it idles at all stops

Clean or replace ( IAC ) Idle Air Control valve or mass air flow sensor and clean throttle body.

have done all three above..still acting up......

Ok. Have the ( Toque Converter Clutch Soilnold) checked. Google that and it will give you the symptoms of what happens to your vehicle when this part goes bad. Sounds just like what your vehicle is doing.

what else could be wrong with it?.......have done all of the above

Sorry have nothing else for you at this time but I will continue to investigate the problem.

Is your Throttle Position Switch adjustable ? Sounds like it is idling to low. And also check vacuum lines making sure none of them are off or bad.