2011 Yukon XL Denali Crank, no start, fuel pump?

[Enoob]

I just had my dealer complete an ECM adjustment following a Mass Airflow Sensor replacement. I was taking it in for a transmission replacement and coincidentally had a issue of it stalling after starting. They did the above and it seemed fine for a day or two. Unsure that is connected, but now I have it cranking and will only start roughly, if I press on the accelerator. I have about 170k on it and have never had the fuel pump changed. I am not getting any codes. I hooked a pressure gauge up to the rail and get an initial reading of 60psi and then a slow steady drop. Drooped to about 20psi and then seemed to stay there. It seems to not always drop that far and now doing it again, it shows about 48psi. I checked my gauges to be sure the fittings are all tight.

Am I safe thinking it is a pump and starting there? I have no problem tacking that job. I am thinking it would be rather preventative if nothing else due to age. Other suggestions/tests to run?

 

[Enoob]

I changed out the fuel pump and what a PITA that is. Seems to be starting and running well now.

 

[Bill 1960]

Thanks for posting the solution, especially since none of us were any help. I didn’t see this until today.

Fuel pumps give some weird symptoms at times on these. I experienced some stalling just one day that subsequently disappeared, followed by intermittent stumbling off idle. But it ran strong and the fuel pressure tested good. A new fuel pump cured it.