93 plymouth voyager won't start!

My Voyager has 180,000 miles. It started stalling while driving 3 times. Then it did again. But wouldn't start again. Before it needed heavy gas to start and then was fine. It tried to turn over, tried 6 times, then would not do any thing no click or return when turning key(should it spring back?). Tried to jump, nothing. Fuses are good. I just don't know where to start.

Yes, it should spring back to the run position. If it's staying in the start position you'll have to replace it regardless. To start with check the battery and starter connections for security and corrosion. If all is well remove the starter relay and check for 12vdc voltage there when you turn the key. If you're seeing a lower voltage you'll need to charge the battery. If you see no voltage you either have a bad ignition switch or neutral start switch on the transmission or the wiring between. If you see voltage as you wiggle the gear shift, it's an indication the neutral start switch is out of adjustment or needs replacing. If you're seeing 12vdc right away reinstall the relay. If it doesn't click when you turn the key, replace the relay. If it clicks check for 12vdc on the small connection on the starter. If you have voltage there replace the starter.

When it was stalling while driving, was it stalling as you slowed down for a stop or while at speed? If while stopping it could be a binding idle air control valve or dirty throttle valve, the EGR system, or a fuel issue. If it is stalling at speed I would lean toward camshaft or crankshaft sensors. Were you seeing a Service Engine light or erratic instruments?

It was stalling while braking 5mph- 30mph. Battery is charged. Is relay under the steering column? My Chilton Guide makes it difficult to find. Any online diagrams?

On Voyagers, mine '93, in the ignition switch, can the spring? of the key cylinder prevent the car from trying to start? Or is it more likely to be the ignition coil? I Have the problem stated above and was going to start by replacing the unseated key cylinder hoping that the existing key switch will work.