I'll soon be reinstalling my fuel injectors with freshly cleaned ones and while I have the rail off I considered painting the sad looking rail.

Is there anything I should know before attempting to paint? I figured on a high temp spray paint.

While I was thinking about that, I wondered if it was a good time to consider adding some kind of Schrader valve so I can check fuel pressure at the rail, in case I was chasing a problem.

What would be the best way to add something like that? I'm assuming simply tapping the rail is probably not a good idea? Has anyone here done it to the AJ16 setup?

 

I wouldn't bother painting it to be honest. It won't look nice and clean for long... And then the oil "steam" in the engine bay. I'd either polish it up or leave it as it is...

 

Yes, add the schrader valve . If you can weld or have a shop weld a boss on the rail, you won't be sorry.
I just can't believe Jaguar's short coming on this.

 

Vee
On the basis that what can go wrong will go wrong, the very safest way is to have a threaded female port fitting installed in the rail into which your fuel pressure gauge can be screwed, but for normal use have a blanking plug screwed into the port. That way, you have no emergency problems when the Schrader fails one dark wet night when you are far from home! But like 44L I agree it would have been a great idea to install such a fitting at the manufacturing stage.
Greg

 

I don't know much about welding. I don't even know where I would take this to get welded. Any tips on where to look? What to ask for? I do want something that I can attach a gauge to, when needed, rather than have a gauge in there all the time.

I'm going to take the suggestions and pass on painting the rail. No use in looking for ways to spend money that is not needed.

Thanks.

 

Or you could get an FPR from Amazon, with a Fuel Pressure Gauge built in, which could save a lot of messing about and be much Safer.

This is just one that I picked out at Random but there are loads to choose from, from about £23.

Agreed about the Fuel Rail, just give it a Good Polish and don't paint it.


Edit: If you don't want the Pressure Gauge on there all the time, you could just unscrew it and then Screw in a Blanking Plug.

 

Why the concern of a failed Schraeder? Most cars have a variety. Five on the tires.
And on the AC ports. But, a welded in bug and a plug would do just fine. Screw in the guage when needed.


As for paint, my vote would be clean and bare. But, ideas jump up:


1. Gun blue.


2. Powder coat.


3. A good brand of engine paint. The good ones fare well.


Carl

 

I had no idea these things even existed! I think this is a perfect and simple solution!

 

Hi Vee

Compared to the OEM FPR they are practically giving these away but if it were me then I would leave the gauge on. (Which would look kinda Cool)

And keep the one you take off in the Boot/Trunk as a Spare.

 

I have used brake caliper paint to great effect on other parts like lower wishbones. It also lasts.

But I do like OB's suggestion of polishing the fuel rail.

 

Not all FPRs are created equal, Vee. Stick with the OEM would be my suggestion, for OEM reliability you have to buy something far more expensive, from a specialist top-notch maker. Then you have to lash it up somehow; all good fun if like me that sort of thing is your hobby, but merely in-needed pain if not.
Greg

 

pix of my FP test , one engine off other with engine running.

its at 45psi

also pic of my adjustable FPR.

a quick test only takes me 4 or 5 minutes, good indicator of possible filter restriction!

 

I value your opinion Greg. I came across this post previously, casting a doubt on the overall quality of the OEM fuel pressure regulator.

https://www.jaguarforums.com/forum/xj-xj6-xjr6-x300-26/aj16-fuel-pressure-regulator-65918/

Grant's opinion carries some pretty heavy weight around here as well...

i was was going to pull the trigger on this guy, even though I'll need to adapt it to the M14x1.5 threads on the existing fuel lines.

https://www.amazon.com/gp/aw/d/B00KQ15K1C/ref=mp_s_a_1_1?ie=UTF8&qid=1487375454&sr=8-1&pi=AC_SX236_SY340_QL65&keywords=fuel+pressure+re gulator+genssi&dpPl=1&dpID=51CQVmV1vpL&ref=plSrch

 

I've been struggling on the best, uhh, easiest way to do this and I've come up with this somewhat pricey solution.

On the return end of the fuel rail, I would insert this fitting between the hard rail (which is M14x1.5 threaded) and the soft fuel hose:


I couldn't find this part with the right threads, male and female, so I would also have to spring for two M14 to 7/16" adapters, which are easy and cheap to buy.

Am I missing a better alternative? I was contemplating going with an aftermarket fuel pressure regulator, but couldn't find one that would fit easily. Its nothing but hard pipe over there with limited clearances. The return side seemed much more amenable.

There wouldn't be any reason for the pressure to drop after leaving the rail, would there?

 

Quite honestly, Vee, about 40 USD on a D Manners FPR that screws straight on and will work perfectly seems to me a far better option that what you are contemplating.
Jaguar Partno_EAC4864*_PRESSURE REGULATOR XJ SER 3/XJS_David Manners Group with Alts
Greg

 

I'm trying to find a way to fit a fuel pressure gauge while I'm in the rail... I'm not opposed to using the OEM regulator, I would just love to find one that allows me to tie in a gauge.

 

Keep the number of joins to a minimum to reduce the rick of leaks.

An FP gauge is a good idea and can be plumbed into the return side of the rail, there will be a pressure drop across the rail but it will be minimal. I would plumb it between the FPR and rail and use JIC fittings.

 

FYI I'm on my third FP gauge. Maybe oil filled would survive the engine vibration better, but mounting it on the body is far more reliable long term. Also note that fuel pressure oscillation also can wear them out. You're supposed to put a damper before them. Usually this is a small bore orifice restriction in the line to the FP gauge.

 

Thanks. If I do this the way I want, I will attach a schrader valve and not permanently attach a gauge to the fuel rail.

If I can find the right fitting or FPR, I would fit it between the FPR and rail, however it seems too tight to squeeze something else in that assembly.

 

Vee i agree , i dont want a FP gage permanent mounted , its only for an occasional test!

i could have mounted mine on the side port of FPR , it would be at the socalled end of reading, but laws of compressed liquid says equal in all directions, be it beginning or end of flow, i'm guessing for our use , maybe at full engine sustained output might be 1psi diff.

an NA engine could care less about it!