Starting problem on a 99 cavalier 2.2 litre

Vehicle died on the way to work and had coded 2 weeks prior with a bad coil and possible injector issue. Tried changing out the coils with no luck, then changed out the crank and cam sensors. Moved on to the Ignition Control Module and then on to the Powertrain Control Module (bought one online already flashed for my VIN for less than half the price of the store bought one). After attempting the relearn process for the PassLock 1 system (in which the theft light never went out), I bypassed the PassLock 1 system by placing a 2k resistor between the two wires specified on a GM website (can’t remember the actual URL but I could find it for you if necessary). This still did not get the vehicle to fire up. Took vehicle to dealership and spent $93 to have it diagnosed. Diagnosis was that the fuel was not getting to the engine due to possible blockage of fuel lines and/or bad fuel pump (though the dealer’s rep told me the fuel pump was bad as it did not run for the tech). Changed out the fuel pump (which turned out to be fine) and have just today verified that we are able to get fuel to the engine but only intermittently. Seems as if the fuel pump only runs once in a while, not all of the time as one would think it would. Any ideas? The relay is fine (brand new) and the other fuses appear to be good as well.

oh also forgot to mention that sometimes there is a buzzing noise coming from the fuse block under the hood when the ignition is turned on, appears to be coming from the fuel pump relay but I’ve changed that out with 2 other relays. Seriously do not know what is going on here and need my car to be running again. Please help!