Summoning the geniuses of the forum: Problem accelerating from a stop / hill, engine stumble [updated]

[davidavidd]

How old are your spark plugs and wires? I did not see them being mentioned in the thread. At that mileage, you should have replaced the plugs at least twice and the wires at least once. I just did mine on a 2017 Tahoe at 91,000 miles, and the improvement is remarkable. My truck was running a bit sluggish and hesitating during acceleration. The plugs I pulled out were filthy.

Not that old, I replaced them 6000 miles ago: plugs + cables + coils (@clubdriven)

 

[davidavidd]

The cleaning helped a lot, at the moment the problem is fixed, it hasn't failed for 3 days.

Sometimes has a rough idle, but I've already ordered the pump and it's on its way from Miami, buying it here in Colombia is a scam, the dealer charge me three times the price plus taxes and I'm sure they also ships it from Miami lol.

Fuel pressure is at the minimum acceptable so the plan is: new fuel pump and flush everything again (fuel tank, lines and injectors). After that I hope to close this chapter.

Thanks to everyone for the help.