LBZ: P0087, Fuel Rail Pressure (FRP) Too Low [Archive] - Duramax Diesels Forum


View Full Version : LBZ: P0087, Fuel Rail Pressure (FRP) Too Low

10-11-2010, 03:16 PM
my friend has a 2007 LBZ with around 100,000 miles. he is running some pretty big EFI Live tunes from duramaxtuner (530rwhp, 460, etc.), and occasionally drives the truck pretty hard along with some heavy towing. the truck has a lift pump, PPE ported fuel rail fitting, PPE shim kit, PPE CP3 pump inlet fitting, intake, exhaust, shift kit and ML converter. why did his truck throw a low rail pressure code with the lift pump and all the little PPE things he has? when he starts the truck you can hear the lift pump, so i assume that means its working. thanks

10-11-2010, 03:22 PM
Hearing it run does not mean its working... First thing I'd do is make sure the lift pump is building pressure, then do a bottle test on the FPRV

10-11-2010, 04:04 PM
Pressure from the lift pump is 15

10-11-2010, 04:07 PM
And the bottle test??

10-11-2010, 04:44 PM
And if it passes the bottle test there is a tsb for the fuel line sucking shut. At the driver side firewall and down by the trans when the fuel gets warm the hose gets real soft.

10-11-2010, 04:51 PM
Check all the factory fuel line. I haven't had another 87 since I replaced that 2 feet or so of it. Even got the fuel hot to duplicate the problem
10-11-2010, 05:16 PM
Is this tsb only for LBZs or is it for everyone?

10-11-2010, 05:21 PM
Is this tsb only for LBZs or is it for everyone?

Here is the TSB for you

10-11-2010, 07:22 PM
Did this just start happening or is it after he started running the tunes?

Whats the lift pump pressure at WOT?

Whats the rail pressure at WOT during/into a run?

Could be too much fuel being called for, not enough lift pump pressure under WOT (i am sure there is unless pump is bad), or FPRV is loose and leaking (bottle test will tell).

10-11-2010, 07:24 PM
thanks guys ill make sure to tell him some things to check

10-11-2010, 07:50 PM
I think that TSB would be for people without a liftpump. I don't see how the lines could suck in when pressurized... Maybe it was a bad batch of fuel and clogged the fuel filter.

10-14-2010, 02:21 PM
my friend cleared the code and said it hasnt came back since. i told him what you guys recommended he do. i dont think its a serious issue like his CP3