shuts down

Have a 2000 Bravada that stops running when get in stop and go traffic. Have traveled into city twice now and ran into miles of stop and go traffic and after a while the car will just quit, they've been very hot days too, usually will pull over for awhile and then turn key start, but not turn the engine over, and it will run for awhile longer then quit, as it progresses the distance gets shorter between stalls. But after it has sat for a couple of hours we've traveled the 65 miles back and had no trouble at all.
Perplexed

Does the Check Engine light come on?

no check engine or did any codes come up

take that back, wife said service engine light came on, but only code was p0410 came up, which is for emmissions air pump

When the ignition coil starts going bad, it'll lose voltage when hot then regain voltage after it cools off.
You might keep a spark plug in the car then when it quits, connect the spark plug to an easy to reach spark plug wire, have an assistant crank the motor while you observe the spark plug for fire.
If it shows a bluish pink spark then you might check the fuel pressure here...

http://i131.photobucket.com/albums/p288/Clunk_/Image026.jpg

Normal pressure is 60-65psi