You mention that the leaking damper was "fixed by a professional".

That o-ring looks pretty sad now that Steve has pointed it out.

Perhaps it, and the one used in the fix, are inferior parts or a bad batch.

It may be that the symptom of the leak disappearing after warmup is accounted for by the seal being more flexible at a higher temperature and then being able to seal better around the flash.

It would be interesting to test for leaks before and after buffing off the flash.

If you find the same flash once you get the installed fuel rail out, then the word BINGO comes to mind.

 

Also that's a huge amount of squash on the damper O ring but it isn't being used as a proper O ring should be -i.e. seated in a groove.
What's the diameter of the shoulder on the damper that the O ring buts against when it's pushed home ?

 

Just to be sure that my comments have not left readers of this thread confused about what we are looking at in these pictures and what are the exact parts that I will be working with soon... By starting this this thread, my plan was to get some thinking started, and give all of us an opportunity to SEE close up, color views of parts identical to the ones all have on our cars. Parts similar to the ones that I WILL be dealing with IN THE FUTURE - BEFORE I took my car apart. It wont be long, before I put the Jag away - for the most part of the winter. In fact, we have a "wintery mix" moving in tomorrow -and I will begin the tear-down process.

Again, these pics are from a different rail/damper/injector system I bought from a salvaged car to examine - and make a plan of action for when I get my XKR's engine spread out all over my garage. I do not know,or have any reason to suspect that the system and it's components that we are looking at in these pictures were leaking fuel when they were in service.

Plums & Steve: The above being said - The casting flash on those Blue O-rings that seal the dampers do look REALLY crappy don't they? There is a small amount of flash on the brown rings that seal the injectors, but not nearly as much. Plums I have certainly considered that the Damper O-rings that were put in by the rebuild service (Injector RX - out of Houston, TX) may have been bad. AND I agree, temperature obviously MUST be making something seal that shrinks back down when the car is cold.
Plums, I also agree that the amount of "nasty flash" on those blue rings is worrisome and if I find that kind of casting flash on the seals that I remove from my car, I WILL use some very fine sand paper to clean them up before putting them back together. But here's my mental position. I DO NOT WANT to take this car back down to the point where I can remove the injectors a fourth time - so once I get the current, leaking fuel rail out of the car - by GOD, I'm gonna be sure those pesky buggers will never have any chance of leaking again!

More information: The damper that is now leaking on my car is the SAME damper that was leaking BEFORE I went to all the trouble to replace it last July. Also, I called Chris at Injector RX last week. He remembered working on my fuel rail. He described what he had done to ascertain that the rail was no longer leaking. He said: "After putting new O-rings on the pulsation dampers and plugging the injector cups, I put 120 psi of air pressure on the rail and left them overnight, underwater in a sink with soapy water... The next morning I didn't see any bubbles or any indication of a leak - so I thought we were good."


Steve: My Father in-law took the Pulsation Dampers that you see in the photos with him this morning when he headed home from the the holiday he spent with our family. He and his wife live 350 miles from our home in Kansas City. He plans to machine (at his far better equipped shop) the plugs that I have been proposing to stop up the dampers. So I cannot give you the dimension of the ring groove "shoulder" at this time. Below, I provided a photo enlargement of the blue O-ring seal setting in position on the Damper. I also thought that the amount of "squish" was pretty huge (Those dampers were REALLY hard to pull out of the cups!) - but, you can see, that there seems to be plenty of room on the damper groove for a larger "smash" then I have normally seen with O-rings.

I'm actually looking forward to getting the problem parts off of my car so I can get more information - and solve this pain in the butt! I just have to find the time - However, as you guys know, it's a really big job, and my 51 year old back is NOT looking forward to it.

 

Please pm me when you get the real thing apart - JIC I miss your exit from hibernation.

 

The problem with testing in a tub of water is that it is a static test. The fuel damper sits perfectly still in the water. In the real world it is mounted by one end and oscillates with engine vibration as well as fuel injection pulses.

 

+1, Plums
and, of course, unless you monitor temperature corrected absolute pressure, it can sneak the odd bubble while you're back's turned.
Been there, don't ask.

 

Steve&Plums: Both of you are absolutely right on with the static test! I had not thought of either of those things - Also perhaps 120 psi was TOO much pressure and he should have checked it after filling the rail with fuel and applied only about 40 psi of air pressure - since that is closer to the actual condition and pressure that the damper actually sees in operation.

Thinking out loud here..... any theories on why his "fix" held for about 1000 miles and THEN started leaking? Hmmmmm, if is WAS deterioration of the rubber O-ring caused by alcohol in the fuel THAT might make since. He DID say though, that he used viton O-rings.

Okay, so let's turn this discussion a different direction if you don't mind.

Please help me think of definitive ways to test the actual rail that is leaking when I get it pulled out of my engine.

Ideas?

BTW, Steve I don't do too much hibernating - when it's crappy weather out there - I'll be in my cozy "little shop of horrors" wrenching away on what ever project is at hand. In Missouri, snow doesn't last too many days - And believe me, as soon as I can get that Jag back on the road - even if it is 30 degrees below freezing, as long as the roads aren't sloppy - I'll get the car out and drive it!

 

Well it probably is a viton seal. But, there are at least 6 different formulations of viton from Dupont. Each one of them has different characteristics. Steve may be able to identify which forumulation you have by the colour.

Sure a seal can leak after a 1000 miles. There is a lot of flashing material that could have be shifting in and out on every oscillation/pulse/bump. If the flashing hung at a bad place, then you get a leak. Sort of like picking at your ear with a q-tip. Sometimes its great, and other times ...

In actual fact the only valid test is under varying pressure pulses and under movement. Even then, passing the test only means it passed the test. Logic would then suggest it will continue to work under similar conditions as long as your friendly UPS driver doesn't bang it around enroute.

Tested components work 99.xxxx percent of the time, and then the shuttle explodes on takeoff.

 

Sorry to mention it again, but you must test it at least at 76 psi, (so 65 base psi, and when running under boost 76 psi).

It’s the older 4.0 cars that run about 43 psi standard.

So far I have not come across issues with the fuel damper though (on jaguars), so it doesn't seem (yet) a common problem.

It may be damaged from the 120 psi pressure as you suggested. Better swap both units if the other one was also within the test.

 

It could be Viton, Blue just means it complies with FDA requirements, but it is unusual.
Preferred colour for Viton now is green or black with a green band.
If your guy has fitted Viton O rings you should be OK with petrol/ethanol mixes but not at all with petrol/methanol.
Some light reading here - http://www.biofuels.coop/archive/viton.pdf

Re testing - if I were doing this I'd use a tracer. The simplest is Fluorescein sodium in water, you can scrounge a little sachet from a Casualty nurse (if you don't know one, this would be a good and unusual approach 'I say, could you possibly find me some Fluorescein sodium for my Jaguar?')
- it is used to test for corneal abrasions.
Water isn't ideal because it isn't very penetrating so add some washing up liquid.
You can still use blanket air pressure to pressurise.
The advantage of a tracer is (like finding A/C leaks) it persists so you'll see it with a UV lamp (again scrounge a bank note tester or take it to an A/C place if you haven't got one).
As Plums says this doesn't test for vibration leakage.

A possible problem from the excess 'squish' on that seal is that it twists as it is fitted (like a Möbius strip) and that can make it leak.
Some silicone grease on assembly would be a good idea.

 

Hey, Fluorescein. That's a good idea it is generally available and fairly priced - even on Ebay. Thanks Steve!


Also Guys, check these links out:

http://www.synerject.com/regulators_dampers.html

http://www.whipplesuperchargers.com/...sp?ProdID=1196


I'd say, those are our dampers.

PDF on second link says the O-ring is a Viton GLT O-ring

 

After reading what the whipple site says about the dampers - I may rethink the removal/disabling of the dampers on my fuel rail. I'm going to call them tomorrow and have a chat about just that. And find out if the dampers are still available new.

 

Hmmm.. that's a real pretty blue seal on the whipple unit.

You may not have seen these notes in the technical drawing:
source: http://www.whipplesuperchargers.com/pdf/3bardamp.pdf

From the synerject site:

Maybe the way to go is to omit the retention clip and used a machined outboard clamping arrangement. If you are reusing yours, then grind off the ears and use a custom machined clamp.

 

Quote from Plums: "Maybe the way to go is to omit the retention clip and used a machined outboard clamping arrangement. If you are reusing yours, then grind off the ears and use a custom machined clamp."

I haven't had the time to call "Whipple" yet... If they DO have those micra dampers in stock at the $50/each price (in the right pressure range) I'll order two of them and put the new ones on my fuel rail.

Here's an proposal for a clamp based on Plums idea... While waiting for a doctor's appointment I free handed a sketch of my thoughts for a clamp to hold the dampers onto the rail tightly. I drew it on a coffee table in the waiting room - on a piece of note paper I asked the receptionist for: I'm certain I was getting some strange looks! Ha!

I took a pic of it with my old iPhone - sorry for the bad focus

 

What happened to good old napkins?

Awww ... I had machined billet in mind .... and make two extra for the inventor

Threaded ears on one side, countersunk for matching socket screws on the other side.

 

Napkins - yes indeed, many of the best ideas no doubt began life on a dinner napkin.

But, use "napkins" provided by a dental office??? Nooooooo Way!

Billet Aluminum? Nice! But there's a practical reason I sketched out a less impressive steel strap and plate design... SPACE!

There is very little vertical space above the fuel rail - the charge-air coolers set very close to the rail and aluminum would probably require a thickness above the rail that would make the fit less certain.

I called the Whipple Charger people yesterday and didn't get someone very knowledgable on the phone - they DO have the Micra dampers available, but the person I talked to didn't seem to have ANY idea that there were two different parts rated for low and high fuel pressure systems - even though their on-line info clearly points this out! More investigation needed.

BTW. I got about two hours into the engine top removal last night, and should make more progress this evening. I'm going to TRY to unbolt the supercharger intake from the back of the S/C without removing the entire Throttle Body assembly and its assorted wires and hoses (so I can just slide the S/C out the front of the engine) If it is possible to do so, a HUGE amount of time could be saved.... I'm not holding my breath though.

 

Saw a picture on the forum where someone had done that. It looks like belt off, coolant pipe at front off, slide SC out front. He claims 4 hours.

 

Hey Guys! Long time... because of NO Time!

Here I set at 12:53am writing you all about wuz up wit my ride...

Plums: No way (that I could figure out how to get that S/C off the top of the engine with out taking the entire intake and T/B system off the car. That damned rear super charger bolt that is sooooo easy to take out with the intake elbow removed is near to impossible to get at with a tool with the intake anywhere near the correct position. I wasted at least an hour trying not to disassemble the intake system - forget it people, just take the damned thing apart!

Well that being said:

Now, I have the engine of my XKR in pieces ONCE MORE.... I sorta feel like a college kid again with my 1970 Plymouth Duster 340 - that always seemed to be in pieces, as I tried everything to make it go quicker - I was fairly successful... She went 12.20s @ 111 mph in quarter mile!

I did ALL the pressure checks on that infernal pulsation damper. Checked it on the car first with a full fuel rail and 45psi of air pressure pushing it and it did not leak. I upped the pressure to 65psi and it began to leak. I could not - for the life of me - ascertain weather it was leaking from the O-ring or the crimp on the damper itself. I hit it for about 5 minutes with 100 psi and it just leaked worse (the damper on the passenger side, bank 1, didn't leak at all.)

After dicking with it for about an hour, I pulled the rail and injectors off the engine. I pried back the keeper clips on the leaky damper and pulled the damper off (though, it did seem a whole lot easier to pull off than either one of the dampers on that ebay fuel rail I had taken apart for the pictures about 10days ago.) The O-ring was the same type of bight blue ring that was on the other fuel rail. The "flashing" was much less noticeable on the ring that I had just removed. I looked at the ring with a magnifying glass and could find nothing apparent wrong with it. So here I am wondering, still.... "Is it the O-ring or the crimping?"

I took a foot of high pressure fuel injection line and attached it very tightly to the little pipe coming out of the damper. On the other end I put an air line fitting. I then filled the line with gasoline and pressurized the line and damper to 115 psi... there were no leaks. I left it at 100 psi overnight - and it didn't leak at all.

By the way AVOS, the dampers that were on my "R" were the same exact rating as the dampers I took off of that ebay "normally aspirated" car's fuel rail (seen in my earlier photos) - 380Kpa - that's only about 53psi. I wonder if the continuous higher fuel pressure of the forced-induction cars - possibly along with alcohol in the fuel deteriorating the rubber O-Rings - could possibly be what has been causing my leaks???

I suppose most people would just put another O-ring on it and put it back together - praying to the "Gods of Coventry" that I just had a bad O-Ring (for the second time.)

That's not me, man. This thing's NOT going to leak again... Not on MY watch!!!

I'm NOT gonna replace the fuel pressure dampers ( I tried that last time with a professional injector service doing the damper "re-sealing") - I'm gonna take them off and seal off the fuel rail "cup" that they are pressed into. I'm sealing the "cup" in a way that they will never-ever again have any chance of leaking (silver soldering) - but (just in case) I'm sealing the "cups" so that if it becomes apparent that the car doesn't run right without the dampers, I can unsolder the "plugs" and try to by new dampers - taking my chances on a new set leaking again... But for now - I'm "breaking-bad" and throwing the Jag EFI engineers' best plans to the winds!

Ahhhhhh! Silver soldering - My first attempt!

A usual, I need the right tools and lessons. I don't
have either.

Pictured are a few pics of the stainless steel fuel rail pressure damper cup blocked off with a stainless bolt from ACE Hardware:

Soldering this this damned thing took me a half hour - But I wasn't going to give this one up till I had something I thought might work.

I've been soldering electrical connectors since I was 13
years old, brazing since about 1995, and welding for about three years
but I'll be damned if this wasn't the most difficult metal securement I have ever attempted!

Finesse and "know-how" are required - and I ain't got either one. But I finally got it... I think

I'll pressure test it tomorrow at 100psi. If it holds, then I'll solder the other side closed.

More exciting info from the bumbling shade-tree mekan-ick later.

 

Morning Max,

The NA cars run the same base fuel pressure, and the 380 kpa is more a pre load of the unit from which it starts to dampen, not the max pressure they can withstand. Don't know enough about these dampers to judge if they are needed or not, but as there is no common issue with them I wouldn't remove them. But on the other hand I also don't know how safe it is to replace one yourself, so can understand your decision.

 

Well, if it wasn't the damper, then it is the interface that was leaking.

There are two notable notes from the manufacturer - not reusable and must be lubricated with non-silicone lubricant during install.

If the o-ring was defective, old or not lubricated then a leak is a possibility. The crimp itself could be suspect.

And finally ... don't forget that the damper does not have to be in that exact spot. It could just as easily be installed at some more accessible spot. Perhaps at the end of a aircraft grade fuel hose with the proper fittings. The connection could be a tee at the rail inlet for example. The other end could be just a clamp because it already works for you in achieving a leak free joint.