my 95 lesabre wont turn over with the key but can be bypassed and will turn over but then wont run please help

Welcome to GM Forum! When you attempt to start it with the key, does the Security light come on and stay on?

How are you bypassing the key to get the starter to turn the motor over?

Please provide more information. Such as does it crank and not fire, does it not crank, does it sound like it'* trying to start but not catch, etc.

Likely a passkey malfunction. Check the security light to confirm. Very common problem. I don't know about lesaber but my 92 olds would run for about 5 sec and turn off. My 98 would not turn over at all. I bypassed both cars passkey using this method:

http://vats.likeabigdog.com/

You need a decent multimeter and ability to do some basic math. Resisters are available at radio shack but unlikely you would get an exact match. I had to run 2 resisters in series and a 3rd set of 3 in parallel to get the right inpediance.