1998 Mercury Sable Car dies immediately after starting

Engine Performance problem
1998 Mercury Sable 6 cyl Automatic 76000 miles

I recently had a fire in the air cleaner assembly. I replaced the boot and air intake tube, then replaced all spark plugs, added Seafoam and started the car. It started right up, idled up to 10,000 (?) Rpm, then died. I started it over and over and it always died when it reached the same rpm. Can you tell me why and/or what to check next? I'm a disabled 60 yr old woman trying to keep my old car running. Any help is greatly appreciated!

beveld