Must be warming up out there...
I have fielded 4 calls from LBZ owners already today and it's not even noon.
1) Had P0087 codes and others. Replaced pump no cure. Replaced injectors and his fuel pressure issues went away. Now he's chasing boost codes. Totally stock truck
2) Has 4 Dmax trucks pulling RV's 2) 2007 LBZ, 1) 2005 LLY and 1) 2004 LB7. The 2007 LBZ's are the only ones giving grief. P0087 both trucks, sudden onset. Totally stock I believe
3) 350k and no fuel pressure problems. Running TS MP-8 (jacks fuel pressure) and called regarding different issues.
4) 2006 LLY (actually LBZ) 300k+ hauling RV's now getting P0087. Has Edge with monitor and uses it to clear codes.
I'm thinking this is still injector related (caller #1 supports this, BUT I also think this may be one of those things like the 2001 where we can do some programming changes to address this. Unfortunately not enough of the fuel psi info is available to do this at this time.
P00087 and GM bulletin PIP4526
I recently received communication outside TDP from another 2006 LBZ owner who also hauls cargo (trailers) commercially. He had been experiencing the same P00087 low fuel rail pressure code (with limp) when the truck was fully warmed up, and while running loaded in the hills. Recently, the problem had been occuring more frequently, with less load...all symptoms identical to those I have been experiencing.
Their GM dealer had previously recommending 8 new injectors due to 'high return rates'. They did perform the physical return rate test with tubes and graduated cylinder. The truck was exhibiting no other symptoms of injector problems - no smoke, no oil dilution, etc. and had 215K miles on the factory set.
They were not convinced, were not willing to spend 4K uneccessarily, and kept on digging for answers.
Finally, another GM dealer they found on the internet had pointed out GM bulletin PIP4526 which deals with collapsing rubber fuel lines, on the draw or supply side. They replaced a section of hose per the bulletin, and have had no further issues with similar loads over similar mountains.
Hope this helps someone scratching their head over P00087 codes, with a fresh new filter and no other driveability problems. I have yet to repair my truck, but am confident this will address my issue, too. Possibly a GM tech reading this could cut and paste the contents of the bulletin in this thread.