When you removed the UIM, did you remove the throttle body to inspect the area behind it? I do not see where you replaced the UIM, which is a very common failure behind the T/B. In addition, the plugs will not fire hot enough to start the engine, once soaked with coolant. If not done yet, change the UIM and then the plugs.
http://www.automotiveforums.com/vbul...d.php?t=681086
Did you see something similar to this pic, once you removed the UIM? If so, you need to replace the UIM!