Fuel issue?

[Blake Sul]

2005 Chevy 2500HD V8 6.0L

a week ago my truck was "acting" like it wasn't getting enough fuel into the engine and just stalled . Next day had about a full tank and it just drop to about empty and i'm now avg about 7 miles per gallon just asking to see if anyone with this truck had an issue something similar? 

[CamGTP]

Well, if you think it's a fuel issue stick a mechanical fuel pressure gauge on the fuel rail and check the pressure. See if it's within spec.

 

Having the tank level go from full to nearly empty in a single day without much driving could be the fuel level sending unit on the pump. They are known to go bad just like the fuel pumps itself.

 

Past that I am guessing at possible issues. It's your truck, so you are going to know the maintenance history and if any trouble codes are present.

[davester]

also check that your exhaust manifold bolts are present.  They tend to break off, and if enough of them do, you can get an exhaust leak that draws clean air into the exhaust stream, making the O2 sensors read lean, and then the ECM will dump fuel into the engine to try to "fix" the lean condition.  Depending on how bad the problem is, the ECM may or may not throw a code.