1991 Buick Regal Car 3 1 Lt Engine Which Will Start Starter Turns Over Battery

Did you check for voltage and ground at the ignition module. Pink wire is voltage goes hot with the key on. Black wire is ground. With bypass ignition, it is the ignition module that controls spark, but, the ignition module has to receive signal from crank sensor, during cranking.

I meant to say the ignition module controls spark during cranking.

YES I CHECKED THE VOLTAGE AND GROUND ON THE IGNITION MODULE CHECKED GOOD

i have also replaced the ignition module

What about the crank sensor? I hate to see you throw parts, but, my thought was the crank sensor.

how do you check the crank sensor and where is it located on the engine?

I believe it is located on backside of engine down low. May have to get at it from underneath. I wouldn't try to test it, if that is the original crank sensor, I'd replace it. Usually the crank sensor is a lot cheaper than the ignition module. If I narrow it down between the crank sensor and ignition module, I always change the crank sensor first.

If you have a scanner that shows live engine data. Crank the engine and look for an rpm signal. That signal comes from crank sensor. Without that signal, no spark and no injector pulse.

An intermittent rpm signal can drive you crazy.

Here is some testing info.