headache 5.0

[TRIT0N]

ok lets start at the beginning, 87 5.0 with aod
runs fine for 10 mins each morning and quits half way to work, restarts, sputters and dies, continues to do this for any whereb from 10 mins to half an hour, we have replaced the module, pick up coil, coil, tested for codes and at first we came up with a few but upon retesting only came up with a code 18 which we understand to be spout connector.
after the car sits for anywhere from 10 mins to half an hour it will restart and more ofetn then not make it the rest of the way to work. although sometimes when it does restart it runs like crap.
one contact suggested the air bypass valve. does this sound reasonable?
any help would be appreciated
oh and yes we here the fuel pump running and have pressure at the rail to eliminate those right off