94 won't idle

19 Rodeo
3.2L v6
4x3
~132,000 miles

I replaced the valve cover gaskets, spark plug tube seals, and upper intake plenum gasket this weekend. when I started the car to back it out of the garage, the car fired nicely but revved up to about 3000-3500 rpm, then smoothly dropped the rpms all the way down to zero. the car obviously shut off but didn't buck or kick or stumble or anything like that when it died, just shut off.

I'm guessing I forgot to plug something back in. I checked everything I could see and couldn't find anything unplugged, at least nothing obvious. Can you point me in the right direction to where I should be looking?

Thanks

sorry... that should read 94 Rodeo and 4x4

also, if I give the truck gas it'll stay on but as soon as I let go of the pedal, it dies again.

so I plugged in the MAP sensor and whatever that module is next to it and the car stays on. however, it idles at 2k now. I've looked and everything else looks as it should. maybe a vacuum leak?

(anybody?)