You didn't mention the year of the truck or model
Bubbles can come from a damaged suction line or a restriction in that line
when you changed the filter in the HFCM, did you lube the o-ring? and turn the cap until it bottomed on the threads?
The fuel bowl should fill within 3 to 4 seconds
it is also possible you have a clogged inlet line at the fuel tank, some of the metal tanks liner would flake off
It is normal for the pump to time out in about 20 seconds without the engine running -- when the engine runs, the pump is continuous
Bubbles can come from a damaged suction line or a restriction in that line
when you changed the filter in the HFCM, did you lube the o-ring? and turn the cap until it bottomed on the threads?
The fuel bowl should fill within 3 to 4 seconds
it is also possible you have a clogged inlet line at the fuel tank, some of the metal tanks liner would flake off
It is normal for the pump to time out in about 20 seconds without the engine running -- when the engine runs, the pump is continuous