Hello,

I have a 2006 LR3 4.4 with 110 K and I need so expert advice.

I have had lean codes (P0170 and P0174) for a while now, they don't seem to affect the function of my truck but I have spent a great deal of time chasing them down. I have tested or replaced most of the intake for leaks, replaced the PCV valve, intake manifold gaskets, hoses (the truck overheated before I got it and needed it). rebuilt the heads, ran cleaner through the system both rail and tank. Inspected, replace injectors and o-rings and replaced the MAF. And flashed the ECU to remove the old programming.

I previously tested the fuel pump, and got 65 psi and disconnected it. Today I decided to dig deeper. What I noticed is after sitting overnight, there is zero pressure in the system. I can disconnect the lines and no gas spills out. Previously I drained the pressure first. Second, when I first start the engine, it holds dead on at 65 psi with little movement. This is when I disconnected it before. But this time I let it run a while, after a few minutes the needle begins the jump, basically down. It never levels out at 65 psi as it becomes a blur. From my observations, it appears to reach as low as 50 psi while idling.

I think I may have a bad fuel pressure regulator. From what I understand, that is part of the fuel pump. Or does this tend to happen on these and I should just get the ECU reprogrammed?

Thanks,

Ovide