2000 LeSabre dies after startup.
 

160,000 miles with newish Fuel Filter.
It starts right up, then dies within minutes.
Then it acts like it wants to start, but doesn't
unless I let it sit for an hour or so.
When it repeats the performance.

I suspect the fuel Pump.
How do I test it?
Any other ideas?

Thanks,
Nevin

Replace the core packs. I had the same problem. I had to sit for awhile until the bad core packs de-energize. Also check the crank shaft sensor and the PCM

Also with the car off, have someone turn the key to the acc position not start while you listen under the car where the gas tank is, check to see if you hear the fuel pump engage.