I doubt that the Gumout is preventing the fuel pump from running.

While the pump is in it's no run mode, I would begin by checking power to it, step by step.

An easy place to begin to check power to the pump is the in cabin inertia switch.
So pull it's electrical connector & check for +12 volts to ground on the DG/Y lead, for a couple of seconds, when you switch the ignition to KOER.

If no power is there, go to the under hood power distribution box & swap out the fuel pump power relay with the A/C power relay & try again.

If you have power to the inertia switch, make sure it's set, so you know power is passing through it to the pump, so maybe give it a thump that'll cause it to trip, (the little red indictor on top will pop up), then reset it & listen for the fuel pump to run at KOEO.

A way to bypass the inertia switch if it's in doubt, is to pull it's electrical connector & jumper the contacts & listen for the pump to run at KOEO.

Once your sure power is on it's way to the pump, but it's still not running, try wiggeling the pumps electrical connector & doing another KOEO test.

If that doesn't do it, try giving the tank. or pump a good thump & see if it'll wake up & run at KOEO.

By then you should have an idea where your intermittent pump problem is.

If it runs after the thump, replace the pump.

Let us know what you find.