93' 4 runner will not start

i have a 93 4 runner with the 6 cylinder 3vz-e, it cranks, butwont start! it was running till i gave it a tune up, dont laugh, i changed plugs, wires, cap, rotor, pcv valve. all wires are hooked up correctly, i tripple checked. i am getting 12 volts into the coil, from the ignition switch(black/red wire) but only 12 volts out of coil. i checked the coil and it tested good. i am getting power into the igniter from the ignition(black/red) as well as the black/white wire. i am lost. everything we checked say it is good, have i overlooked somthing simple? also we tried to check the codes, and nothing, i mean my check engine light does not come on at all. i do not know if this is part of the problem, or if it is a seperate problem?

See the threads:

http://www.automotiveforums.com/vbulletin/showthread.php?t=929043
and
http://www.automotiveforums.com/vbulletin/showthread.php?t=929717

ok,i tried everything that made sense, nothing worked, i ended up having to take it to a shop, now i was not happy with this but i am in the army and had to go to the field. so the shop calls me and tells me they care not sure ( this is a toyota specefic shop) what it is, and they need to look farther. they finally call me and tell me that they figured it out. it was my mass air flow sensor? ok i am boggled. they replace it, not only does it start, but it runs better than before, i am happy that it runs better, but can someone tell me why my maf sensor controls the spark from my coil? is this somthing that is toyota specefic or is this normal all the time? i have asked this to everyone i work with and have gotten many different answers.?? can someone explain this, i hope at least that this helps someone else. thank you, regardless.