96 Z28 WONT START JUST CRANKS!

Question

what does this mean car wont start is it the opti, or crank sensor?

Answer 1

If the engine crank and does not start this can be from the opti or crank ,but you also have to include  ignition coil, ignition module, The best tool to determine why there is no spark is a labscope, or voltmeter, or test light. The most available is a test light. In order for ignition to happen there is a low resolution and a high resolution, when cranking if the fuel pump comes on and the injector pulse,  (test with a test light) (or even feeling the fuel injector pulse with you fingers) ,then you have low resolution,without a high resolution you code up a P1371,and a replacement of the ignition module will be the solution. Leave the crank sensor alone, it purpose is for misfire detection. and does not contribute to produce spark just to inform the PCM of a misfire.