2002 chevy venture no spark?

I have a 2002 Chevy Venture with  3.4 that has no spark. It also has no codes. With the scan tool I can see the 7x and 24x crank sensors generating a signal. I have checked power and ground to the ignition module. Checked for a/c voltage while cranking from both crank sensors and the cam sensor. I have also voltage dropped all the powers, grounds, 12volt and 5volt refernece cicuits, to and from the ignition module  and pcm. I have also tried new coils and ignition module. Any input would be greatly appreciated. Thanks, John

Just to let everyone know the truck had a damaged tone wheel on the crankshaft due to internal engine problems. I remove the entire ignition system and hooked it up on the bench and made it fire. At that point I removed th oil pan and found damage to the ring where #1 is. Installing an engine is more than the truck is worth! To the junkyard it goes!!!!!