the other morning on my 02 dmax went to start it up and it sounded like a rod was going to come out of the block... noticed the fuel gauge read below e and i know for a fact that it had diesel in it. turned it off went in the shop grabbed a can put less than 2 gallons in it turned key on it read over a half a tank and the truck ran fine all day... later that night we left from eating got in the truck it did it again and i knew it had fuel in it... tried turing it off and on nothing would get it to stop so i drove it across the street showing e and low fuel light blinking and added more diesel and it still would not stop and the fuel gauge will not stop blinking showing e. I am certain that the erratic idle is somehow related to the truck thinking that its out of fuel... will someone please help
if it matters truck has 111k

02 check for fuel leaks make sure your nieghbor isnt scamming free fuel from you because it is 2.70 a gallon. there should not be any corrulation between the gauge and computer putting you in limp mode gm would rather you run out of fuel. knock is probably a bad injector or multiple injectors, suggest having codes checked. 100,000 miles is the life of injectors.

i was hoping you were not going to say that...I head the injectors are really high

Don't assume the worst. Have your codes read and go from there. The injectors are not that bad if you do them yourself. Granted they are a bit expensive, but they are not that bad to do. Change your fuel filter if it has not been done lately. You could have some poor fuel. If I remember correclty there is an issue with the harnesses on the sending unti at the plug. Do a search on that and see what comes up.

the other morning on my 02 dmax went to start it up and it sounded like a rod was going to come out of the block... noticed the fuel gauge read below e and i know for a fact that it had diesel in it. turned it off went in the shop grabbed a can put less than 2 gallons in it turned key on it read over a half a tank and the truck ran fine all day... later that night we left from eating got in the truck it did it again and i knew it had fuel in it... tried turing it off and on nothing would get it to stop so i drove it across the street showing e and low fuel light blinking and added more diesel and it still would not stop and the fuel gauge will not stop blinking showing e. I am certain that the erratic idle is somehow related to the truck thinking that its out of fuel... will someone please help
if it matters truck has 111k

sounds like you might have a sending unit going out or a bad gauge cluster. i know when i fuel up my gauge is slow to move sometimes taking 10 mins to go from 1/2 tank to full. ive also heard some other guys complaining about this so it seems to be common.

as far as your loud knock is it cold out when you went to start it? diesels are loud and "knockie" when there first started in the cold. also what type of oil are you running?

can you please explain your erratic idle a little better? does it fluctuate or "search" when your sitting at an intersection or in park? could be a fuel pressure regulator going south.

This sounds like something that happened to Me. Just a lil water getting past the filter. JUST!!!!! Check my thread from yesterday titled (water injection).