I need to know where the computer is on my 94 B2300? on 1994 Mazda B2300

I've changed fuel pump and fuel pump relay, still doesn't start sometimes! And like now, it won't start at all! I was told that the computer was the only other alternative! You can hear the pump come on and it always starts, but when you don't hear it come on, you know it will not, may be 10 minutes or days before it will start up! Thank you for your time and help.

Asked by for the 1994 Mazda B2300
You need a MECHANIC to check this out for you! ... Many possibilities for this problem!..... Computer is the 'least' likely suspect! .... Possible Ignition switch, ECM relay, inertia switch issue, wiring or connection problem, failing fuel pump etc.... Don't throw parts at it blindfolded... Cost way more than testing!