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18 - General Information ( Chris Burdo,  June 7, 2005 )

18.1 - Helpful Restoration Tips ( Jeff Warner,  April 29, 1998 )

You must isolate where the fumes are coming from. There are
essentially three areas to look -- Boot , bonnet and underneath.†
I have had all 3 so here are a few suggestions.

After you run the car and at a point when it smells the worst,
simply stop and open the boot, stick your head in and take a smell.
If it is a strong odor, then this is where you start.† If you do
the same to the bonnet area and it is a strong smell than that is
where you start. You must really get into it at this point to try
to isolate it by where the smell is strongest.

If you do both and you don't get the strong aroma then you need
to check the fuel line that runs from the boot to the bonnet as
well as the tank(s). I just found that my line was broken and it
was pumping petrol into the boot where it was soaked up by the carpet.
Because it was soaked into the carpet, I never found the leak until
recently when I lifted the car and shook the line.

If you suspect the boot area, then what you need to do is simply
turn on the ignition and check for leaks.† I had two leaks on my system.
One was where the plastic line went into the tanks (I have 2 tanks on the 420)
and the other was the connectors on the SU pumps. I replaced the plastic
line with metal flare stubs into the tank and I replaced all of the lines
with new rubber in the boot.† This seems to have eliminated most of the
smell from the boot. Carefully check where the lines connect onto the SUs.
Sometimes the petrol seeps past the Stainless clamps.

In the bonnet, you will occasionally get a stuck float (or a
Saturated float) which causes the smell.† When I had this problem, I took
the carbs off and I used sand paper to clean the rod the float slides on
as well as smoothing the inside hole in the floats. I found that after 35
years the rod had gotten a bit rough and I felt this was not helping the
operation. Also check to see if the arm the float contacts is set properly. If
one of the legs is skewed to the other it will cant the operation and the
petrol will not shut off properly. With the domes and pistons out of the
carbs, you should be able to turn the ignition on, have the pumps pump and
the flow of petrol stop at the level of the jets.† If this is not happening
tha this may be your problem

The basic operation is simple: you will only get a smell if the
petrol is exposed to the air.† You must go over the entire delivery system
to see where petrol is meeting air in an unauthorized place and manner.

Addition from George Camp, June 14, 2005

Do not forget the 3.8 MKX had an extra area to watch.
There is a valve on the rear bulkhead to prevent drain back from one
pump to the other.

I am actually referring to the ''Non-return valve in the
Rear bulkhead. If you look at J32 (parts manual) p 279 item 33 you
will see what I mean. The later external pumps had built in non-
return valves so the part was eliminated but the Lucas E-2FP had no
such valve and indeed the first external pumps also had none. Without
the valve they would transfer fuel to the unused tank. I do not
have time to look it up but there was a tech. or parts bulletin
that covered the change. The point of my post is this valve is
often overlooked and is prone to leaking in its aged condition.

Paul Scott adds on June 17th, 2005:

I would like to add the following possibilities, although I
am not sure if they all will relate to the Mk10:
Banjo fittings on the carbs and fuel pump can weep, they may
need re-flattening (lapping on emery on a mirror), I have
never really been able to get the fiber O rings on these
banjo fittings to seal properly and have had to resort to
adding fuel proof gasket sealer. On the 340 and Mk2ís the
fuel filler cap should not be vented, the tank is vented
through an overflow pipe that comes out of the side of the
filler pipe and is vented out under the car, clipped to the
bottom of the petrol tank. If the cap is vented then the
fumes can find their way into the boot. The Auxiliary
Enrichment Carburetor (automatic choke) is open to the air,
the fuel level is the same as the level in the float chamber
and the petrol sits in the bottom of the air intake.
I converted to manual choke as on the E-types, which has
vastly improved but not eradicated my fume problem, starts
from cold much better though.

18.2 - To Modify of Not, That is the Question! ( Jon Garde,  )

The XK engine has a cast aluminum head with hardened steel valve seats pressed in. Valve seat erosion, which occasionally occurs in older American engines, is the result of the valve welding itself to the valve seat in the absence of lubricating lead, and taking a small chunk of the seat when the valve opens. In these engines, the valve seats were machined directly into the soft cast-iron of the head, and relied on lead additives to provide lubrication for longevity. The original valve seats installed by Jaguar are hard enough to withstand this abuse, and will give years of service.

18.3 - Jaguar Diseases ( George Haynes,  )

One characteristic of switches that most people are not aware of
is that they require a certain amount of current to work properly.
Under normal circumstances a certain amount of oxidation will build
up on the switch contacts which has the effect of insulating the
contacts from each other.

Packing the switch with dielectric grease and designing the
contacts so they wipe each other helps solve the problem, as
does wetting the contacts with mercury.† However, none of these
design techniques are present in the SU fuel pump.† It needs to
rely on current flow to burn through the oxide layer.

If you put a transistor in the circuit you eliminate the current
flow through the points so they don't burn and wear out but this
creates the aforementioned second problem instead.

The points in the SU fuel pump are perfectly capable of handling
the 3 Amps that the pump draws, but they get burned by the high
voltage arc that is generated when the points open (just like an
ignition circuit).

The solution is simply to install a suitably sized (3 Amp) diode
across the coil.† Such diodes are available from Radio Shack as part
numbers 276-1141 through 276-1144.† Diodes are polarity sensitive,
so connect the diode lead that is marked with a band to the coil
terminal that connects to the positive side of the battery.† Forget
the transistor and just use the points to carry the current.

There's no need for the capacitor if you have the diode.†

In spite of the fact that I love to add electronic devices to our cars,
this is the best solution for this application.

18.3.1 - More Jaguar Diseases ( Pater Havas,  )

After reading your column on Jaguar Diseases, I felt compelled to share the results of my own research in this area with your readers. While the field is certainly broad,a nd there is no lack of subjects to study, I feel it is imperative to classify the various afflictions, infections, syndromes, and behavioural traits before new models come out and corrupt my research. Below are a few of my most recent findings. I welcome all comments from like minded field researchers.
Spontaneous Part Regeneration SPR:
The innate ability of any Jaguar part, when dismantled from the car after failure
and replacement, to "heal" itself and be suitable for service again if left in a closed dark place for long enough, or immediately upon the part no longer being available either rebuilt of NOS from any source.
A) Immaculate diaphragm healing.
B) Spring height re-establishment.
C) Piston Ovality suddenly acceptable
D) The inclusion of the phrase "Close enough" in your vocabulary.
E) A .22 feeler gauge appears thin.
F) Sand blasted Pot metal parts look almost as good as new
G) The sure and certain hope that "Maybe THIS time it won't break" becomes dogma.
H) A loss of memory for exactly how many miles the part already had on it, but the conviction that it "wasn't much".

Scroungers Scourge:
This affliction usually occurs early in the restoration, in what Psychological experts have come to call the "Collection" phase. It is typified by the patient scouring auto-jumbles, and junk yards for ANY period parts and / or accessories. Said material is then acquired, and although it has no use whatever in the restoration of the car at hand, is trotted out at the merest suggestion of the drop of a hat with the wry comment that "You've never seen one of these." or "I know lots of people who would kill to have some of these.". After appropriate billing and cooing over the object(s), the patients status has risen immensely, and the material is then re-shelved to await the next victim. There is no known cure. Early stages of this affliction are characterized by people commenting that they 've " .got two of those back home in the barn." when shown a particularly desirable piece at an auto-jumble.

The developed ability to instantly tell which nuts and bolts on a Jaguar are metric, which are not, and which wrenches can be cross-referenced to round the shoulders of both. Often mis-diagnosed as Hexasnapophobia, or fear of reading wrench sizes and frequently confused with rank stupidity, the afflicted person can often be heard mumbling: " I don't get it. It worked on MY car"

Biomechanical Bonding:
Dismissed by some as a myth, researchers are increasingly convinced of the existence of this strange phenomenon, which to date apparently is prevalent only with British made Automotive paraphernalia. Symptoms include a close attention to detail when re-building a particular part with the factory approved kit, and complete instructions.
The most severe evidence is with Lucas Generators , S.U. and Stromberg Carburettors. When correctly assembled and installed with precision, the part will have so bonded with it's maker, that it will steadfastly refuse to function on it's own, and "Just want to be taken apart again". There can, therefore, be no substitute for slap-dash assembly.

Double Optipupilotomytosis, or "Bush Babies Syndrome":
A condition caused by driving Jaguars at night, relying on Lucas to show you where your dash-board is. The victim's pupils often expand to ten times their normal size, requiring them sometimes to wear sun-glasses at night when arriving at their destination. Sufferers often prefer the company of their own, to avoid the possibility of being suddenly blinded by lighted cigarettes, flash cameras or inadvertently stepping in front of a BMW.

Sportsmans Crook-neck:
A painful and embarrassing physical condition, caused by Jaguar drivers cocking their heads back, while leaning forward, to actually see the end of the front wing when pulling out of a parking space. Sufferers are frequently confused with erudite snobs, due to the "Nose in the air" stance they assume in public. The experienced Jaguar driver, however, will instantly recognize this for the debilitating condition that it is, and take pity on the afflicted.

Retrovisionary Trauma:
A syndrome shared with Sail-boat owners. The disease is typified by an inability to remember anything about past Jaguar ownership, except through a rose-colored fog.

Merlin Syndrom
The conviction that normal physical laws do not apply to common consumable parts on Jaguars.
They wear out due to:
A) Anger
B) Fatigue
C) Somebody else's incompetence
D) Magic.

The inability to recognize that common consumable parts on Jaguars do not wear out due to:
A) Anger
B) Fatigue
C) Someone else's incompetence
D) Magic.

18.4 - Racing the Big Saloons ( Larry Martz,  )

Yes, it is standard practice to do the brake seals etc while subframe is removed, and set-up the handbrake properly. Use coppa ease on handbrake pivots etc. Set-up handbrake before adjusting cable., but we are away ahead here :-)

For removal of subframe, I found a (long) piece of 4*2 to push through the subframe as it is lowered, and lever the rear down, to stop it from tipping forward. It is very front heavy.

1st remove grease nipples from bottom of hub-carrier, otherwise they will get broken off! Note shims between diff and drivehshaft, this is your wheel camber. There are shims at inner end of lower arm, shims for bearing set-up on the wheel bearings and on the lower fulcrum on the hub carrier.

Take your diff to a shop to be done, it probably isn't worth the time (unless it is OK of course).

All the other parts (and I mean every bearing and seal), UJs, arm bearings etc are cheap, and worth replacing. A good rear end makes the car very driveable :-) Some UJ's have grease nipples, some don't.

The most difficult is the wheel bearings, The removal of inner race of the outer bearing on the hub (as opposed to aluminium hub carrier), is a b*****d whether steel or whire wheel hub, and may need shop help, depending on what you have access to. I have known it fall off, which probably means the hub is useless. everything else can be drifted, I used a hydraulic press.

On setting up, you must understand how the end float of the hub bearings works, you do not need the special tool referred to, it is just a spacer of an exact dimension (50 thou), you can use any spacer as long as you measure it. You cannot tighten the rear hub bearings just by doing up the big nut tighter. The endfloat is governed by a spacer and shims. Don't believe anyone who tells you otherwise. The book says shims are obtainable in 3thou sizes, but I have seen them in 2 thou sizes

The preload (as opposed to float) on the hub-carrier lower bearing shaft. When you drift out the lower shaft, use a dummy shaft. If you dont, there are thin shims in there in the centre, which will get dislodged otherwise, and then mangled as you push a shaft through. The taper bearings in here often have dried up with rust, as the seals can be poor, and the water gets in. Also, the bearings only revolve by a few degrees by comparison to normal bearings.

If you are buying in kit form of parts, beware there are two sizes of outer oil seals for the bearings, changeover 1B5166, 1B25707, 1B55701, 1B78500 depedning on 3.4/3.8/LHD/RHD.

Shock absorbers/springs can be done any time, and the set-up is really a personal preference.

18.5 - Genevieve: A Love Story, MKIX Book ( Kon Kakanis,  March 24, 2003 )

The late Larry Martz put me onto a book called "Genevieve - A Love Story"
several years ago. It was a self published book relating the story of a Mk
IX bought new, sold years later, and then re-purchased and restored.

I found my copy by registering on a few bookshop sites under 'Wanted'.
Since then, a notice arrives a couple of times a year telling me it is
available again.

18.6 - Differences of a MKX to a 420G ( Robert Meyer,  December 26, 2002 )

Long time ago, maybe in the beginning of December 2002
Andy wrote: >> Mk X vs 420 <<
Can someone(s) please expound upon the differences
between the Mark X and the 420?
They seem to be extremely similar, yet the 420 seems
to be higher priced/more sought after.
Andy Litkowiak

Hi Andy, my answer seemed to be rejected automatically
as I made some faults. So I try again:
To distinguish between Mark X /420G and 420 seems to be
a problem even for automobile journalists and some
Jaguar book writers.

The outside distinctive features between Mark X and 420
are visible even from a distance of several meters.
First you should distinguish between 420 vs 420G.
The much bigger 420G ("BIG GEE") really had only few
exterior differences to the Mark X, as the "BIG TEN"
was its direct predecessor and for a first view had
not more than a new name.

So a mixing up of Mark 10 vs 420G would not be such
a big fault.

There were only few changes with the 420G:
Additional chrome lining on the sides
with small signal lamps on front end,
grille with stronger middle bar,
smaller lamp glasses, new wheel caps as well as
two tone colour as desired. That was all from outside.
Interior and technical changes were some more:
Upholstered dashbord top with central clock
and new technical details will learn from my "BIG JAG -bible":
JAGUAR Mark VII to 420G
Author: Nigel Thorley
Bay View Books Ltd, Bideford, Devon, GB
ISBN 1-870979-41-9

The first Mark X series had a 3.8ltr engine,
followed by the second with 4.2litre engine.
The third series, the 420G had a 4.2litre engine like
series two, but a new name.
To distinguish between 420 and 420G you first should know,
that the 420 was a noticeable smaller car.
To make it simple - imagine a 2step evolution of the Mark 2.
First step: Give it a new back end looking like a Mark 10 boot
and you'll get an S-Type.
Second step: Give it a front end looking like Mark 10/420G
and you will get a smaller brother of a Mark 10/420G,
named Jaguar 420.
Distinctive features visible from outside:
- 420 had rectangular horn grilles instead of round ones,
- 420 showing B-column, not visible at Mk10/420G,
- 420 opening only motor hood, Mk10/420G opening complete
front with grille (comparable with XKE).


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