97 Z24 cav help please

I turned the key over today and nothing happened but all the power works. So I took out the starter had it tested witch was bad so I replaced it and still the same problem. I bypassed the key ignition by putting jumper cables and a toggle switch to the starter. It started once but after that it cranks over but doesn’t fire up. If can help me I would appreciate it.

well, if it cranks but doesnt fire, it could be a few things. Listen to see if your fuel pump is turning on. if it is, then have someone crank the car and see if your getting fuel to the injector. if you are, the next step would be to check for spark. those are the first two things i would check. let us know what you find out.

it only cranks if i use the jumper cables to the starter .if i dont use that and try with the key nothing happens it doesnt even crank but the power comes on

Having 14'ish volts is different from generating the amperage needed to start a car. Your battery is probably dead, go to an autozone or an advance auto, they test batteries for free.