I have a 2003 Yukon with a V8. My kids left to fill it with gas as it was down to 1/8 tank though the fuel light was not on. When they left it ran ok cold, and then rough as it warmed up. They made it to the station, put in four gallons, then started it up and tried to return home. It died, and after it sat, it started and idled poorly, then died. I let is sit over night and it started right up. I drove it home (about four blocks) and as it warmed up it started to stumble then died. It has fuel pressure as I can hear the pump engage before starting, and there is fuel at the valve on the engine. I replaced the fuel filter and ran some "Heet" through it. It started again while it was cold, then as it warmed it started to stumble then died again. So it appears to be heat related but I have no idea where to start.
It is Sunday and I am trying to fix it today so they can drive to school tomorrow. Any suggestions?
Thank you!

You need to put a fuel pressure gauge on it. If it'* below 55 PSI it won't run well.

Thank you. I will check it out.

So I replaced the fuel filter and the air filter. Same issue, started when cold then died as it warmed up.
I let it set today and I just went out to see what would happen if I tried to start it. The engine will crank but not start. I pulled the cap off and checked the flow of gas at the maifold and I have none. The filter is facing the proper direction, and I did not kink a line or done anything else. Now I am really puzzled. I am thinking that maybe the pump finally went out.
I was also told possibly the MAF sensor, but I do not have access to a code machine so I am stuck. Any advice would be appreciated.

fuel pump sounds like, but like 75 said a pressure gauge would tell you wont start under around 52 and wont run good unless over 58 or so. normally run in the 60'* with all good parts, and they do not like running low on gas, the gas keeps the pump cool and not having it accelerates wear

Put a gauge on it today. Fuel pressure at 64 so that is good. Put a trouble code meter on it and it had the code for bad catalytic converter. So now I am pricing those. It looks like a lot. Does anyone have a good online source?
Thank you!

you check rock auto? we have a 5% discount thread

https://www.gmforum.com/general-gm-c...279335/page12/

I know in California it'* illeagal to sell a used cat but in Wa I wonder with that new of a truck the recycle yard might have one.

didnt they have a recall on those, seems like there was alot. i dont think i would want a used one, i think they breaking up and clogging with only like 5 years on them

The government going to be cracking done on selling cats. They are going to make it harder for after market companies to make them. Due to emission concerns. I know in NY. After market can not touch them till there 8 years old or have 80,000 miles on them. It is also illegal to sell used cats here.