The dealer is correct, the injectors have to be leaking fuel bad enough that the CP3 (High pressure Fuel Pump) cannot keep the rail pressure up.
The desired vs. actual fuel rail pressure test results that they are showing above look really good, therefor it has passed the test even though the injector balance rates on cylinders 2, and 5 are out of spec.
I have dealt with the same issue on both LB7's that I have owned, and had to replace the injectors on both of them myself because they passed the FRP test, just like yours.
You could do what I did and wait until the last day of the warranty to take the truck in, hoping they will be bad enough by then to fail the test, but you'll probably waste another $100 on testing just to find that they still are not covered.
I hate to tell you the bad news, but I believe you will not get anywhere trying to get them covered by GM.
Good Luck! - Titus
Last edited by JoeSmith21; 02-07-2011 at 11:53 AM.