2011 Chevy Silverado Starting Issue HELP
 

I am experiencing cold starting problems with my 2011 Chevy Silverado 1500 4.8l V8 that lead me to thinking that the fuel pressure may be leaking somewhere. The truck is hard to start after it has sat for a while say overnight or like 8 hours. Its seems it is worse when it is cold outside. The problem has recently started occurring and has seemed to get worse. Once I go to crank the car, it doesn’t crank the first time then the set cranking time is disabled so you have to hold the key. The starter motor turns fine and then it finally cranks then bogs down for a second at 200 rpm’s, then fires up to 1500 rpm’s like it should. It idles rough for about 15 seconds before it smooth’s out. You can see the antenna shake when it does that. Once it cranks you have to step on the gas petal to keep it from stalling. If you try to put it in reverse quick it will stall. If you give it gas while it is cranking it seems to crank easier. After that it runs perfectly fine. It does not do it when the engine is hot, nor does it idle rough when it
is hot. So that is what leads me to thinking that the pressure is leaking out
of the system because it acts as if there is no fuel there. I’ve had the
battery and starter checked so that eliminated that. I took it to the
dealership and they couldn’t figure out what was wrong. They hooked it up to their diagnostic system and it couldn’t find anything wrong. No codes are showing up. I let it set overnight there so a technician could crank it in the morning to try to figure out the problem. They suggested that I have the throttle body cleaned along with the fuel injectors and that might fix the problem, but they couldn’t guarantee that. . They never checked anything with the fuel system. I guess they didn’t think that was the cause? But it wasn’t doing it as bad then as it is now. It didn’t stall then or not crank on the first try, just bog down when they looked at it. If it were a sensor, I would think a code would show up. That’s what makes me think there is something wrong with the fuel system. The truck doesn’t
act up once it cranks for the first time so I figured it wouldn’t be the fuel
pump. Is there any way of testing if the fuel pressure is low. Or do these sound like symptoms of it. Here is a video of it having the problem. At the end you can hear the engine finally crank and hear it “bog down.” The first video is what it was doing when the dealer looked at it, and the second is what it is doing now. Anyone know what could be the problem?