Mechanical advice please!!!!

Ok first I have a 1990 4Runner 3.0 3zve. I was having a problem with cylinder 6 not firing, so all the signs pointed to a bad exhaust valve. So I tore it down, replaced the valve (it was not seating), and lapped all the valves. Everything went smoothly and when everything was re-assembled I started it up.... and this is where I'm stumped. Problem 1 number 6 is still not firing (it has spark, air, and fuel). Problem 2 the idle is acting like I didn't connect a vacuum line ( idling at 1500 rpms and dropping to 1000 rpms in quick succession). But I can't find a vacuum line out of place. Anyone who has had a similar experience, I would like to know how you corrected it! Thanks in advance!

 

Well I looked farther into it and I still have no compression in 6 and I used the starter fluid trick to hunt down any vacuum leaks. All lines are in good order but my idle is still acting weird. At a cold start it stays just above 2k then very slowly started to drop all the way down to 600rpms and tryes to die. While it was idling I disconnected the sensor on the air filter and it started to die as it should. Then I unplugged the air sensor on the intake manifold and the idle smoothed out for a min then tried to die.