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Trying to set up to test the fuel pressure on my 97 x300 XJR-6.
Can see return pipe at fuel pressure regulator but not sure where and how to get to the fuel supply from tank so as to be able to connect/splice in a fuel presure tester. Non sc loooks easy but not on supercharged.
Any help very welcome please
Thanks
Dave.
The line going into the back or aft fitting of the horizontal fuel rail ( containing the fuel injectors ) is at the regulated pressure of 43 psi at idle and goes up to 46 psi on throttle up
The fittings are hard to come up with but Al_Roethlisberger came up with the solution as he has the supercharged engine
My solution drills a hole into the FPR fwd fitting which is also at the regulated pressure
I have had a fuel pressure gauge fitted for many years as shown in the attachment with no leaks/problems at all.
You require -
: Suitable gauge with 1/8 npt connection (common & easily obtained)
: inline barb connector with 1/8 npt port.
You then cut the rubber fuel line leading up to the fuel rail and insert together with gauge.
You can leave it in place at all times, it gives you an instant reference when experiencing engine problems.
I finally managed to make my own version of the fuel system pressure test rig for the XJ40 cars.
See the photo below. pressure gauge, a piece of fuel injection hose and various fittings I ended up having to buy a M14 x 1.5 die from an ebay seller
Last edited by JensenHealey; Apr 20, 2023 at 08:35 PM.
Reason: added photo of M14 x 1.5 die
xjr-6 fuel pressure test method
