I suspect that my fuel pressure might not be what it should and I'd like to measure with an external gauge to confirm what the electronic sensor is telling me.

Had my fuel rail been blessed with a schrader valve, this would be easy, but the ability to troubleshoot your car is bad for the environment so now it's time to get creative.

I am soliciting the collective wisdom of the forum on what's the best way to tackle this.



At first look I thought these were rubber lines and thought I could splice into them with the gauge T fitting but on closer inspection, they seem to be nylon fuel line with a rubber sheath around them.

It's hard to tell exactly what they are. The OD of the rubber part is 12.75mm (0.5"). Does someone out there know how this line is made, and what size it really is?

This is the gauge and fitting I *thought* I would use back when it looked like regular rubber fuel line. I'm not married to the hose fitting necessarily but the gauge needs a 1/8 npt.



Appreciate any thoughts on where/how to tie in.

I'm hesitant to cut the line and try splicing without really knowing the size and having a definitive plan for what to do next.

 

You first.

I'll bet it would work if you wouldn't mind the gauge being underhood. I've replaced fuel lines on a previous sports car before, and it's not a scary thing as long as you triple-check your fittings before cranking it. And even then, if you see a leak, you've got time to shut her down before the engine gets hot!

That being said, someone more knowledgeable about fuel pressures here will hopefully steer you toward a better answer than poking this with a stick.

 

I'm less worried about leaks than I am about lopping the end off of some 12 million dollar special Jaguar part and feeling like a moron.

Under hood is fine, it's a diagnostic tool so I wasn't planning to leave it there forever.

Idea #1:
I did some digging and it seems like the fuel pressure sensor is cross listed with some Ford cars, including early 4.6L Mustangs, so I think this would fit the rail. I am also pretty sure it would interfere with the intercooler / secondary air temp sensor, which is too bad cause it would have been easy. Might be useful for the guys with N/A cars, however.

Trick Flow® Fuel Rail Adapters: TFS-27021 - trickflow.com

Idea #2: Make up a Rube Goldberg adapter
Thing is, I'm having a hard time figuring out what the sizes mean for these springlock fittings.

Dorman lists a 11mm and 14.2mm version of the fitting with a hose barb and when I measured the springlock fitting on the car and the shank is 0.556", so close to the 14mm size.

There are lots of them available from places like Summit and Jegs that say 3/8 or 5/16 but that doesn't correspond to any real fitting size that I can tell. Maybe they mean the hose size? But if they mean the hose size, what does that have to do with anything, they all have AN fittings?

These are the only two I've found that actually mention 0.550 in the size:
JEGS Performance Products 103116 JEGS Fuel Injection Fittings
plus
JEGS Performance Products 103115 JEGS Fuel Injection Fittings

Idea #3: Replace the line with an AN set
Another option would be to replace the line from the hard plumbing to the fuel rail and add in an adapter for a pressure gauge.

Anyone know what type the circled fitting is?

 

This is so Rube Goldberg that I had to share it.

It took 5 AN fittings + a gauge but it works. Doesn't require any splicing but you can forget about closing the bonnet.

 

Done this on non-Jaguar.

IMNSHO, the most important general criteria is to NOT create a hazard. Top of that list is not whether one can make a leak-resistant connection, but whether one can be certain that the connection and any added components will not deteriorate from vibration, heat, or other rudeness and create a fire after months and years off the priority inspection list. Competition cars are a whole 'nuther animal - get an eyeball laid on 'em REALLY OFTEN.

For a daily driver, use of a sender to a remoted meter - both of a sort already in-use on the vehicle or one near-as-dammit alike ... sort of goes against the grain vs the simplicity of a direct-reading meter on a tee and length of fuel line ...

But ......it is an approach way less likely to lead to a fractured fitting, cut, abraded, or burst line that sends your investment - and maybe yerazz - up in flames.

JM2CW

 

 

Hi there,

I came across your post when researching the same problem I am having. Were you able to find a solution to the leaking fuel regulator problem and if so would you share it with me?

Cheers,
Ergin

 

There is no in-line fuel pressure regulator in the returnless system. That is a pulse damper.