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I am experiencing a drop in actual fuel pressure vs commanded fuel pressure after my ECT reaches 170 degrees (give or take a few degrees) I have several datalogs that confirm this. I can start the vehicle in the morning, even cold mornings in the mid teens without the engine being plugged in and FP_D is always even with FP_A on my EFILive V2. Both read 59 MPA. I can leave the truck idle for 30 minutes or more and both stay consistent. The problem starts when I start driving and within 5 miles of driving the actual fuel pressure begins to fall. At a steady speed of 55 mph the commanded pressure will be in the 70-80mpa range and the actual pressure will be in the 35-40 mpa range. I have verified my Air dog is delivering constant pressure to the CP3 via a fuel gauge. I actually just upgraded the CP3 to a new 10mm. The truck has compound turbos and 45% over injectors. The ECM is a CM2200 with a custom tune. I have run this tune for several years without this issue. After driving and arriving at my destination, I can let the truck idle for 5-8 minutes and the commanded and actual pressures will even out again. I can then take the truck back out for a drive and pressures will match again for a few miles until the temperature rises to the 170 degree range. I put a pressure relief plug in for testing purposes and it made no difference.
