We changed ignition switch 1992 Z28 chevrolet camaro because it was having trouble starting, when we turn key it only buzzes but why wont it start?

The electrical part of the ignition switch is faulty

A couple of things can be the cause. You could have an issue with your battery connection, or your ignition switch is dead. Ignition switch issues tend to kill all the power to the car. They can go without warning. It's located on the driver's side on the steering column.

IF AUTO CHECK PARK NUETRAL SAFTY SWITCH IF STANDARD SHIFT CHECK CLUTCH PEDTAL SWITCH

you seem to have some problems in the core of the security system (the TDM or BCM). There is a great write-up here: http://newrockies.ca . That was the only way I was able to save my Park Avenue

did u check .to make sure all the wires on the bottom of the steering cloum are hooked up. and make sure the ignition switch is the correct on ,if it has the fuel security chip on the key some gm models have a chip in the key this controls the fuel pump ,,whit out it the fuel pump will not turn on

If the key turns, that's all it needs to do. Check, with a test light, to see if you have power to the starter. It could be a dirty loose battery cable, or a faulty cable, or a fuseable link in the positie cable that is gone. It could be the ignition switch itself. Not the key and tumbler, the switch on the steering column. You'll have to do some checking.

ecu needs to read that chip...

be more specific... won't turn over, turn over but won't start, do you hear a clicking noise?

i want to ask is there is any possebl to jump the starter and run the car without using the ignition switch ?

Hi Candie, if you have air, fuel and spark it should run. Getting to the fuel side-"is fuel getting into the engine?" Your ignition may work, your starter may work, fuel pump may work, but if you have an ignition key with a resistor inside it (little silver piece of metal in the plastic of the ignition key) the key, it could be bad and will shut down the fuel injector. It's part of the security system if some idiot tries to break the steering column to steal your car. It won't run.
I have a 92 Z28 with a 350 and I had to get a new ignition with resistor and correct resistor ohm key. About $400.00 bucks but if you search around Z28 forums there are ways to bypass this for less $$ if you want to.