Starting got in the car one morning and it smelled like melted rubber or plastic and when i turned the key on everything worked but when i turned the key to start the car it did nothing i bought a new starter and hooked it up and it still did the same thing i don't know what all is in between the ignition and the starter but all of the fuses in the car and under the hood are good, i am lost on it and would really like some help if you have any ideas i am very good at changing parts but i lack on diagnosing the problem. it is a 95 chevy cavalier with 171000 on it but runs great until this happen.

Holly, hold the switch again then follow the smoke smell, check battery cables and clean them both ends.

every car comes with 2 keys --use the spare key

Unusual for a rubber smell could it be plastic? I would suggest possible a wiring loom that has either shorted and melted or has touched a hot component and melted. If you can smell burning with the electrics on but the engine off it is probably a shot and you may be able to trace with sight and smell with just the ignition switch in. This can cause issue with starting as it could be a feed to or from the starter, an imobiliser cable or just the ecu seeing an electrical fault and not allowing you to start. An unto electrician should be able to advise if you can't find it. You don't say if it is turning over but not firing or not turning over at all
hope this helps

Check under the car and look for a plastic bag that may have melted on the exhaust.

You may have burnt the starter up. They will burn out if run excessively. If the switch continues to act up and get stuck, you will need to check that out. Might need a new switch. I had a similar problem in a Honda, drove 15 miles with the starter still engaged-it really fried it.

Burnt smell after starting 2013 Chevrolet Equinox. Turned key starter turned over slowly then started drove car however strong electrical burning smell after starting pulled over seen smoke coming from under vehicle. Car wouldn't start even with a jump starter just clicking sound then nothing while horrible smell of burnt electrical from under the hood. Towed it home it just clicked once. Lights, horn, flashers dash and power locks all working fine never had any problems. Thoughts starter or ??

check your alternator,power steering or air conditioning belts, unless you picked up whilst driving from the road any plastic bag onto the exhaust pipe and stuck and melts on it.

it's probably the ignition module. I had a car that did that all the time. I went through everything trying to find the problem and finally came across it. Its usually melted on the bottom or smells burnt when it's bad

Cat or other obstruction in fan belt.

Check your owners manual for the location of a fuel pump reset switch,sounds like the vehicle was trying to protect itself. Also, find location of fusible links,they can be fuses in-line to the battery,ie a fuse holder or look like a heavy wire that melt when too much current passes through it.