I have a stock early '06 SS 2.4l auto. I purchased it used almost 2mo ago. I have had the fuel sending unit replaced and the ecm reprogrammed ( due to CEL-lean fuel condition). Since then it has developed what seems like a loss of fuel preasure at WOT with less than a quarter tank of fuel. Then gets worse as the fuel level drops. I don't really know if it did it before the ecm reprogram because I had not let it get low on fuel.

I took it to the dealer a couple of weeks ago and they replaced the injectors. It still did it. I took it back last week and they said the fuel sending unit they installed 3 weeks earlier was defective. They replaced it. I got it back yesterday and it still does it. If I keep driving it, it gets worse and worse, to the point it almost dies just trying to give it any gas at all. I'll be taking back again. Thankfully it came with a warranty.

Mind you it does none of this with more than a quarter of a tank fuel, it runs perfect. Does anyone have any thoughts or maybe has had this happen to them. Any info or help would be greatly appreciated.

 

Well my thought on that are the pick up(for the fuel) in the tank is not sitting in the right position,
Maybe installed 180 deg off or bent and that why you starve for fuel at wot(gas goes to back of tank)
Going up a hill with a quarter tank create problems?

 

it would be easy to confirm rather than speculate with a simple fuel pressure gauge.

 

I agree if you can see it while driving some how.

 

get some long hose and tape the gauge to the windshield.