I replaced my ignition and my car turns over but does not start

I believe it is the ignition lock cylinder. the part located next to the steering wheel that you insert your key into in order to start your car. we replaced it because I had bad tumblers and my key would get stuck sometimes and not turn.

So now you have a new key to use .. That new key is NOT compatible with the vehicles security system, (anti thieft) so the engine is NOT going to start! .. Contact a locksmith and explain what has been done... Locksmith should be able to make a key that will work .. Locksmith will need the old key AND the new key to do so... Good luck with it!