1999 Chevy Silverado Popping in the injectors

I have been experiencing alot of problems with my truck when out running on the interstate it does great.But when I get into town and stop at redlights and it idles for any period of time it starts popping through the injectors and dies on me.I have to let it set for about 5 minutes and then restart it and it runs fine till it sets and idles for any period of time.I have changed fuel pump fuel filters air filters spark plugs mass air flow sensor and the oxygen sensors.But still cant figure it out.Any suggestions would be greatly appreciated.