While driving engine shuts off

My engine stalls all of a sudden every time I am driving the past 5 months. The instruments panel still shows the typical red light of the alternator and other warning lamps but the engine looks either starving for fuel ( which I doubt much because the fuel pump is always working with its noise audible to me) or the electronic ignition is failing instantaneously in an almost systematic mode because it never reaches a terminal problem so that my car mechanic can follow and track nor does it stop happening. It is pretty embarrassing when I am waiting for the green traffic light to move but it fails to turn and all those drivers behind me start the noise of horns. Sometimes it takes a few seconds to restart again (putting the transmission on N) but most of the times it takes some whole 2-3 minutes of continuous cranking( using the starter motor of course) that I had to replace the starter motor 3 times in a row only this past month! I tried replacing the crankshaft position sensor, TBS, MAP sensor, Throttle position sensor, ignition key lock( both the mechanical one and the black unit attached to it on the left side of the steering wheel complex), I even replaced the whole Electronic Ignition set including the two coils and the control module along with their containing plastic cover. In some cases it worked alright for a brief time once I implemented the replacing act ( the ignition switch, for instance|) but then it simply reverts back to the annoying symptoms. I am perplexed: is it the PCM? Is it that aluminum case beneath the dashboard drawer next to the front right door or is it some other control module buried deep inside the dashboard? A loose earth wire or a wire making a short circuit may be? I tried a scanner that works with my old and almost obsolete DLC( having only 3 pins/wires) two times in a row at two independent auto scanner workshops but it simply says( The scanner couldn't communicate with your DLC). One important symptom to include, when I crank the engine using the starter( and the engine takes too long to fire alright) the miles/kilometers pointer to the right side of the RPM one shoots up although neither the engine is working right nor the vehicle is actually moving, there seems to be some short circuit here if I am not mistaken. The engine backfires sometimes and there is a smell of gasoline around the engine.