2007 XC90 3.2L AWD Pinched Fuel Line Help Needed

brbrob · Post by **brbrob** » 27 Oct 2024, 20:03

: 2007_Volvo_XC90_3-2L_Fuel_System_Diagram.PNG (157.34 KiB) Viewed 631 times

Would appreciate it if someone could check out this diagram I put together and let me know if I am on the right track or can point me in the right direction. Thanks in advance.More detailed explanation of the issue.Won't start eventually throws code P0087 Fuel Rail Pressure Low.. verified this is the case.Already replaced the Fuel Pump, Fuel Sender, Fuel Filter, Fuel Pressure Sensor, and Mass Air Flow Sensor for various reasons. (Auction Car with multiple issues.)Came across a thread that stated the fuel lines can get pinched on these. So loosened up the fuel tank retaining bracket and jiggled fuel lines around (1. Fuel Feeder Line from Fuel Pump to Filter, 2. Delivery Line coming out from Fuel Filter, 3. Smaller Diameter Line going from engine to fuel tank, 4. Larger Diameter Line going from engine to fuel tank).
After doing this the vehicle cranked, fired, and started.Then I tightened everything back up (fuel filter retaining bracket, fuel tank retaining bracket, etc..) and we are back to Fuel at Rail Pressure being low.Remove the quick connect from the Fuel Filter Out, verify receive fuel pressure before and after fuel filter. All good here. Time to loosen the fuel tank and trace the lines.. only cant see anything without dropping the entire tank.With some more aggressive adjustment of the Lines 3 & 4 was in fact able to detect that Line 4 was pinched/collapsed.Now I am at the repair/reassembly stage, but it is unclear to me how these lines are meant to be routed especially since there are two different lines (2 & 4) with the quick disconnect on them that either one could go to the Fuel Pump.And I am not entirely sure were line 3 is going once it gets routed behind the tank.Any help or guidance is greatly appreciated.

brbrob · Post by **brbrob** » 29 Oct 2024, 20:29

Updated Diagram.. Still a work in progress..
Thank You to John at JustAnswer for his assistance thus far.

: UpdatedDiagram_10-29-2024.PNG (168.26 KiB) Viewed 613 times

brbrob · Post by **brbrob** » 30 Oct 2024, 13:42

Reading a post in another forum the user Sokniw has this information.

the line running off the fuel pump to a T, T splits and goes to the the fuel filter back to the fuel pump and goes the other way to the fuel rail

so the diagram would be like this...
Can anyone verify?

: T.PNG (115.02 KiB) Viewed 609 times

brbrob · Post by **brbrob** » 02 Nov 2024, 08:15

Current setup of Fuel Lines is with the T.

: T.PNG (115.02 KiB) Viewed 598 times

Also created an electrical diagram for the PEM and Fuel Pump.

With the PEM connected the Fuel Pump is not turning on.
If I disconnect the PEM I can hear the fuel pump engage.

Diagnosing this further it seems that the larger blue wire splits to the fuel pump and the PEM.
With the PEM connected the voltage reading at the red X is 0 VDC.
With the PEM disconnected the voltage reading at the red x is 12 VDC and I can hear the fuel pump engage when turning the key switch.
Disconnecting only the blue wire to the PEM the voltage reading is 12 VDC and the fuel pump engages when turning the key switch.

My understanding is that the PEM controls the voltage through the ground.. so my assumption is that this is what is going on?
I have a new PEM coming today and will do a parts swap as I am at that point of frustration..

brbrob · Post by **brbrob** » 02 Nov 2024, 14:08

Fuel Management System / Engine Management System Diagrams

FuelSystem_EngineManagementSystem.pdf: (118.2 KiB) Downloaded 64 times