2013 LML Fuel Rail Pressure Drop

[HeavyD]

Hey Guys,

Wanted to see if any of you have run into this before. While on the dyno yesterday we discovered that my fuel rail pressure drops off dramatically once I hit about 2550 RPM's. I'm not throwing a code currently but have set the P0087 low rail pressure code in the past (pre lift pump install). Yesterday Rail pressure dropped to 6K and still no SES light or code. Truck pulls hard until that point and then obviously falls off once the pressure drops.

I have a 2013 GMC LML/Allison 27K miles on the OD with the following mods. EFI Tuned- full delete, EGR bypass, down pipe back exhaust, Air Dogg 4G-165, Sumped 60 Gallon tank, Stock fuel filter by-pass. S&B Air Intake.

Any help would be appreciated.

Thanks,

[GMC-2002-Dmax]

Weak Cp4 ?

Too much fuel being commanded.

Something off in the tune.

That would be my top three guesses.

Good luck

[Road]

Pull the regulator out of the pump and check for metal debris. Too bad you voided your warranty.