Starts but won't stay running

Try another key if you have one not a new key. If the other key does not work you will have to scan it to see what is wrong with system. Anti theft is the problem. You will need a regular scanner not an auto parts one as they wont read that. I think that old system you can by pass with a resistor look on you tube or online for it. The newer systems you cannot.

No chip in key. Three wires to ignition switch not two wires like most GM's. How do you bypass or rig to work. I know they sell kits or to rig by installing (value) resistor in line on two wire. Not familiar with three wire. Acting as if doing same thing as not getting signal from key switch.

Keithall3