help!

[young_2010_chris]

alright so ive been chasin my tail on this issue for a couple months my tahoe is throwing the codes :runnin lean on bank 1&2 anf muliple cylinder missfire it...it has a delay startin so my first thought was fuel pump so i hooked a gague on it and wen the truck is off it goes up to like 55psi then starts dropping and goes all the way to 0 can not find a fuel leak anywere from the motor to fuel pump and she runs a little ruff and idles ruff only things i can think of is maybe injectors leaking or somehow is there a leak on the pump inside the tank...what do u guys think its driving me crazy! and i
dont want to buy one thing and it b the other dnt have the money rite now...help me out guys!!

 

[SunlitComet]

If the pump is ruuning continuously and goes up and then down I would look for fault in your fuel regulator section first.