1996 won't stay running no more then maybe 5 to 10 seconds any help with this plz
i replaced key part and the theft light blinks and turn off normal but will not stay running

 

The ignition switch and the BCM are matchedto the resistance value the switch sends. This replacement switch likely has the incorrect value for the BCM to recognize for the security system. That's what happens to the car .... shuts down the fuel pump ... when the security system is activated.
You may have to take it to a dealer to see if the BCM can be programed tomatch the replacement ignition switch.