Engine Stumbles then returns to Life

MK4 VW Jetta. When driving the engine cuts out for a second then resumes as if nothing happened. This occurs when the fuel level is less than 1/4 tank. Fuel pump and fuel filter replaced - still happens. I’ve been told this vintage car has a problem with the “coil pack” (Low voltage in, High Voltage out (spark plug wires) - sort of a combination coil/distrubutor. While inside the fuel tank I noticed what the manual refers to as a Siphon Jet Pump. I can barely see it, but was thinking I should remove and inspect. Today the car just quit on the freeway. Added fuel to the tank and it would still not restart. Had to tow it home. At my wit’s end. I plan to check for spark tonight after work, but barring any problem like that any thoughts?