The flex plate issue isn't with the ring gear and teeth. It's with the square notches in the outer ring. Different engines and years use different numbers and spacing of those notches, but that is irrelevant if you used the original flex plate.
It is possible for no fault code to set related to the crank sensor just from cranking the engine. The missing signal is more likely to be detected as a running engine stalls and coasts to a stop. When you have no spark and no fault code related to the cam or crank sensors, you need a scanner to view live data to see if either signal is listed as "No" during cranking.
As an alternative, you can monitor the voltage coming off the automatic shutdown (ASD) relay during cranking. That voltage can be measured at any injector, the ignition coil pack, or either smaller terminal on the back of the alternator. You will see 12 volts there for one second after turning on the ignition switch. What's important is if the signals are showing up from the crankshaft position sensor and the camshaft position sensor, that relay will turn on again during engine rotation, (cranking or running). If it doesn't turn on during cranking, it's a pretty good bet something is wrong with one of those sensors or their circuits.
Sunday, April 19th, 2015 AT 10:31 PM