1993 jeep grand cherokee limited starts for 2-3 seconds then dies. new fuel pump and crank sensor. It will run if ether is sprayed in intake. Fuel pressure is good. Can not "feather" gas pedal to keep running.

Okay, the possibilities are great. need to narrow it down a little.
If it fails to crank over it is likely the battery.
If it cranks over ok, but fails to start it is either lack of fuel or lack of spark.
the Quickest way to identify lack of fuel or lack of spark is to spray in a 2 second dose of starting fluid into the air intake. If it fires up then dies in this test it is lack of fuel most common suspect is fuel pump relay or fuel pump.
If it fails to fire up on the starting fluid test it is lack of spark. Electronic ignition trouble shoot procedure from your shop manual for your VIN number will be required.

Check the crankshaft position sensor, i have repaired 3 Jeeps (after the owner spent a lot of time and money replacing fuel pumps,TPS, and many other items) then got frustrated, brought it to me and within an hour it was running fine with a new CPS

Do you know if the pump is getting power from the pump relay ?

Does the check engine light on your dash light up when you turn on the ignition, before trying to crank the engine? Does the fuel pump come on for a second, and prime the fuel lines, when you turn the ignition on? Does the fuel injector wires get the pulse signal from the ecu while cranking? If not, your jeep ecu might be in need of repair. It's a common problem with that generation of grand Cherokees.

need injection cleaning,bad injector,bad gas.thank you

Try the M A P sensor. I had a jeep that did the same thing. It would start up and run for maybe the count of two and shut off. It was the map sensor. If I remember correctly it measures humidity and barometric pressure and stuff like that to tell the computer how to mix the air and fuel ratio.

It could be the security system or maybe a crank sensor.

Disconnect and replace fuel filter.With filter disconnected have someone momentarily turn key to on position to see is fuel pump is working.Make sure you have lots of rags,a drain pan and safety goggles on

first check fuses, then check injector pulse, get back to me

Jeeps have a part called the crank sensor, when working properly it senses the electrical feild produced by flywheel. This crank sensor which is located on top of the tranny bell housing has been known to go bad. When this crank sensor goes bad the CPU does not get a crank reference and the computer will not fire the injectors. This crank sensor will fail under high temps and if it is old will fail also when cold.
You have to find out if the injectors are getting a pulse when the car does'nt start.