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What is foamy, looks like sour cream melt, is found in the SU carb holding cup blocking the flow, leaves mould like stains on the sides after it is mucked-out and settles to a fine white powder when dry.??
Seems to be forming in one of the two side cups of the carbs and when cleaned out and new fuel added has returned to block up the workings again.
Has a yeast-infectious pond-scum charm to it, not.
Hey Aden . . . are you serious? I had to go check the date as I felt sure we had got past April 1. LOL. Given your related "timing oddity" no-start, I'm feeling you need to go back to basics to ensure you have fresh, clean fuel from tank to carbs, check camshafts to TDC and t/chain lash, then set static BTDC ignition timing. Only then, tune carbs. Done methodically, 1 step at a time, the XK has few gremlins . . . but attacked haphazardly, you will struggle.
Something in teh fuel you have,or have had in the tank.
Ethanol comes to mind, but usually that is a Black sludge.
Dried old fuel in a tank/s, that have dried up over the years, and not cleaned properly before new fuel being added, and it is washing the system as it goes, and causing you much grief.
It's odd because clean fuel went in at one stage and was running clear and then just noticed this again the other day, and it does seem to only be in the right hand Carb.
It's like sour cream and dries to power. A chap helping me with it (who has a few Jaguars himself) was extremely puzzled by it... bit grossed out too.
Looking at the snap in the other post of your carbies, I see the breather pipe travelling along the cam cover, and then up to the front.
I suggest removing those 2 hoses, plug the vac ports AT the carbies, then look inside those hoses for your SLIME. I reckon it may be coming from the breather system.
If you are referring to the slime being IN the fuel bowls, FORGET the above, not related.
Yes, in the fuel bowls.
I presume a low and high pressure system each require different filters? A low pressure being finer.?
Think I need to add in-line filters and it seems the main fuel filter might be a high pressure one and the reoccurring issue with stuff in the fuel bowls could be all manner of gunk from the tank.
Most fuel filters are based on a Micron medium size. EFI filters are always a metal style, and larger, as they are changed about every 100K kms.
EFI filters are HI pressure, and a finer medium than the traditional carby filters.
ALL filters will plug up quickly with crud from the tank/s, but larger ones just take longer than the smaller carby versions.
Draining the tanks via the drain plugs, and swilling them clean is the only way.
This "stuff", whatever it is will be having an affect on the fuel and its ability to "burn", when needed, so cleaning the source is a priority in my opinion.
From afar, my guess would be a slurry of metal and a solvent. Drying to a metallic salt.
Pot metal, such as found in many carbs does that when in contact with other than nice clean fuel. Water as the solvent???
Agree, it starts with the tanks, as Grant opines. Neat. Messy, and a bit dangerous, but quite doable is the task of draining out Jaguar tanks. Been there, done that.
f only it were that easy to get the fuel out of my Jeep's plastic tank to replace it's failed pump sender module. No drain. Resists old tech siphon hose. Can't get one wet!!
So, I'll open a line and run the pump. Percussuion maintenance urged it to pump.
Will it last, not really. A must if the car is to be reliable.
As side note I found a lot of rusty water in spare wheel well and no clue as to how it go there without wetting the contents of boot above. Later discover further leaking from the abandoned pipe from the un-used left fuel tank. One opening the tank base plug found 2 litres of rusty rain water. I'd been cleaning and sealing the right tank inlet as in use, but ignored the left and it was draining water to the boot. That Thai Laska feel
Upon drying out over night the white powder residue again becomes visible. Blew some muddy fuel gunk in my eye while trying to clean the clogged inside of this pipe. very blocked and filthy. hard to be sure its clean.
That needs to be clean and have some fresh light oil in it to about a cm from the top or the car will struggle to run, as that assembly you are holding with the main needle in it will not want to move and richen the mixture as you open the throttle. If its stuck you will get plenty of spluttering and leaning out as you try to add power.
If you follow this link and go post #6 GGG has put a downloadable PDF there . Explains cleaning/rebuilding and tuning SU's with pictures.
Once you have clean fuel getting to the engine bay it would be a good idea give the carby's a once over.
One of the things you should pay attention to when putting them back together is centring the needle/jet assembly. You may get lucky and have it fall in place, but if not there is a good video by John Swift at University Motors on Youtube. Its about MGs but SUs are SUs on any car.
04-21-2017, 01:04 AM
VD in the SU
