XJR575 with weird starting problem

Reply Subscribe

Thread Tools

Search this Thread

May 8, 2026 | 12:45 PM

#61

k-xjr575

Thread Starter

Member

Joined: Feb 2019

Posts: 55

Likes: 4

Quote:

Originally Posted by RoverJoe

You are correct, the LPFP is energized when the door is opened so there's no delay in starting.

on this point , let’s say if this signal interruption lands up being an issue ( after I put in all new OE parts), then is this an easy fix ? Or will this be a trip to the dealer kind of a thing

May 8, 2026 | 01:01 PM

#62

k-xjr575

Thread Starter

Member

Joined: Feb 2019

Posts: 55

Likes: 4

Quote:

Originally Posted by Vasara

The long pipe on tank might be the "balance" pipe between sides of the tank. The middle shaft tunnel separates the bottom part of the tank.
The balancing is made by "JepPump" effect using return fuel flow. If the balancing hose is lose, your pump side will run dry and your dash still show fuel. (two floaters combine the level)
Not sure what level the free flow of fuel stops because of tunnel, but i think its more than half tank.
This is well descripted on X351 Service and Repair manual

would you have a schematic or an excerpt from the manual that I can look at that’ll help me understand this better. The black tube that I had questions on comes out from under the white filter housing that’s immediately below the lock ring on the outside. It’s pretty short in length so I am not sure if it’s the balance pipe .. one end is hooked up to the nozzle u see the filter housing and the other was free floating in the tank (now connected onto the nozzle of the pressure relief valve as noted in @clubairth1 pictures .

if it’s relevant , currently the car has less than a quarter tank of fuel and seems to start up on first crank following my 2 step process of start button press without cranking followed by start button press with foot on brake to crank . FWIW, the low fuel pressure warnings initially started with the tank more than 3/4 full and persisted even after it was full .

May 8, 2026 | 05:27 PM

#63

Vasara

Veteran Member

Joined: Mar 2020

Posts: 1,125

Likes: 360

From: Finland, Helsinki

Hi,
Check Sticky section of this forum. You will find x351 Service and Repair manual. Its extreme good and usefull for any owner. (and big)
(i am in vacation on Spain and with bit limited gear)

May 10, 2026 | 12:35 AM

#64

JHendo

Junior Member

Joined: Jun 2024

Posts: 20

Likes: 4

Quote:

Originally Posted by k-xjr575

In addition to my previous reply above, the tank looked very clean with hardly any debris in there. When you mention getting eyes on the filter, does the black part come out of the white housing that it sits in? Or is it one preassembled unit ? If I do land up needing to clean the tank, I am guessing then it will be a trip to the dealer? Or is there a way or a "tank clean" procedure that allows it to be performed with the tank still in place?

I was referring to the pickup screen. Any larger debris in the tank would be caught there, and any fines would be caught in the actual filter. Either can have this issue, only difference is the size of the particles potentially causing the issue.