Pontiac Repair: 2001 GrandAm GT V6 3.4L Wont Start, crank pulley, side firewall

Question
Car will crank, but not start. I have replaced the crank sensor and tested the ignition module (tested good), replaced plugs and wires, when checking for spark at the plugs, there isn't any! There are no codes and prior to changing the crank sensor the car would start on occassion. Is this the module or could it be the ignition switch? Any help would be appreciated!

Answer
Hi
There are 2 crank sensors on this motor.
There is one located behind the crank pulley(24x).
There is another one (7x) located on the bottom of block, on the back side (firewall side) in center.
It has 2 wires, purple and yellow.
That would be my initial guess. If your scanner can observe data, watch for engine ROM's and also watch the 24x and 7x signals.
Hope this helps.
Good Luck
Pawl