91 olds 98 doesn't start

When I turn key nothing happens. I jump the sellonoid and engine turns over but won't stay running. I checked all ignition fuses and they are good. What next? Please help.

Welcome to AF, do you have the security chip vats key, does the security lite on the dash stay on?

Yes I have chip key, but no security light. I did clean ignition and key with alcohol and the car started. I am still not convinced that was the problem. I believe the ignition cylinder, or wires are. Very intermittent problem.

Correct, that is a possible cause, if you test the resistance of the chip, then make up a matching resistor from Radio Shack components, it can be substituted on the body side connector of the wires from the ign switch, this will bypass the key cylinder to help pinnpoint the problem. BTW, back down the font.