Does anyone know if the '80 XJ-S has a vacuum storage tank somewhere? I’ve noticed
lately that at prolonged low vacuum (when I’m accelerating up a hill for
instance) the vacuum door to the center vent closes until I let up on the
gas.
On a positive note, I’ve finally got my instrument cluster bright enough! In fact, I’ve got to use the dimmer because it’s too
bright! And I have retained the green bulb covers. I didn’t like the appearance without them.
I replaced the 194 bulbs with a higher (only slightly) watt bulb. I also added 2 additional bulbs, one in the hole that is part of
the cluster but never used. I have 5 complete clusters and all 5 were the same. A piece of white tape blanked off that particular
hole.
Adding that one bulb was easy. Just plug one in. That lightened up the speedometer side but did nothing for the tachometer side. I
had the cluster completely disassembled so took the opportunity to put aluminum reflective tape in almost every nook and cranny I
could. I also modified/removed some of the plastic baffles hoping to get the light to bleed between adjacent areas in the cluster.
It still wasn’t good enough for me. It was better but the tachometer was still the dimmest part of the cluster.
That’s easy to see why as it has only one bulb lighting it from the factory. I decided to add another at approximately the 7
o’clock position of the tachometer, on the beveled part of the cluster. It was easy to cut a square hole, install the bulb holder
and wire it to the circuit on the cluster. I did also have to install the green bulb cover to keep the look consistent throughout
the cluster.
It turned out better than I could have hoped for. Thanks to Kirby’s book, I changed the bulbs used in the warning lights to
different wattages and that issue was solved a couple years ago. I can even see my turn signal indicator during the daylight. And
I have the tiny pre-HE indicator lense! I used Kirby’s suggestion to use bulbs of varying wattages depending on what was desired.
For instance, I used low wattage bulbs for the high beam indicator and rear window heater indicator. I used higher wattage bulbs
in areas that I wanted to make sure I would see them. All bulbs were available from my local NAPA dealer.
Next on the agenda is brightening those switches beside the clock (or beside the trip computer for those of you with one).
The vac cannister is forward of the wheel well on the passenger side, it’s under a removable panel. I would doubt the cannister is leaking. I would be more inclined to believe you have a leak somewhere in the vac lines (rubber connectors or a valve) in the engine bay. The old Brit rubber can only last so long with continued exposure to heat and the elements.
David
From: “Ron Kelnhofer” rkelnhof@execpc.com
Date: 2002/10/01 Tue AM 09:25:12 EDT
To: “XJ-S List” xj-s@jag-lovers.org
Subject: [xj-s] Vacuum Canister and Dash Lighting
Does anyone know if the '80 XJ-S has a vacuum storage tank somewhere? I’ve noticed
lately that at prolonged low vacuum (when I’m accelerating up a hill for
instance) the vacuum door to the center vent closes until I let up on the
gas.
My '85 has a vacuum tank which serves just the AC system. The tank is
mounted within a small cavity on the firewall. The cavity is accessed
from the engine bay by removing a plate that is mounted behind the
windshield washer reservoir. You’ll recognize the plate by the fact that
it has a vacuum hose coming out of it (or should).
Best regards,
Rob W-M
85 XJ-S, “ITPURS”
<<<<<<<Hi Ron,
Ron Kelnhofer wrote:
Does anyone know if the '80 XJ-S has a vacuum storage tank somewhere?
On my car there is a vacuum tank in front of the right front wheel. It
is connected to the power brake system.
Does anyone know if the '80 XJ-S has a vacuum storage tank somewhere?
I’ve noticed
lately that at prolonged low vacuum (when I’m accelerating up a hill for
instance) the vacuum door to the center vent closes until I let up on the
gas.
Hi Ron,
Yes, there is a vacuum reservoir in the A/C unit, and it sounds to me
that you have either a faulty Non-return Valve (located in the vacuum line
between the rear of the right intake manifold and the plate behind the
window washer reservoir) or a vacuum leak between the Nonreturn valve and
the A/C.
Neat lighting stuff! When I finally get into the lighting (somewhere
around #32 on the list), I’m going to add a light in parallel with the entry
lights so I can see into the black hole that I fumble the ignition key into
at night.
Dave Osborne
88 H&E XJ-S (PURR)
Carson City, Nevada
I have the same problem with my 1994 xj40, going up hills i loose vacuum to items, like the defrost flaps controls. I have seen a canister on ebay but i don’t see anything like it on my car. Can any one help? My service manuals don’t show a vacuum hose routing diagram either.
The only vacuum components under my hood, is a white stripped vacuum line on
the manifold that has a T in it, one leg goes through the firewall the other
leg of the T goes to the electro mechanical valve that switches vacuum to
the EGR valve. Also a hose with a yellow strip that comes out of the
firewall that goes to the coolant valve under the intake manifold. Or is
the non-return valve missing?
Thanks for your help
Mark
Kirbert
(Author of the Book, former owner of an '83 XJ-S H.E.)
9
On the V12, the vacuum check valve is within the hose barb itself that screws into the manifold. And it jams all the time, either open or shut. You can tell it’s not a simple hose barb because it has a hex around the base for unscrewing it. If you have something similar, disconnect the hose and unscrew the fitting and see what’s up.
Kirbert
(Author of the Book, former owner of an '83 XJ-S H.E.)
11
Nope, that’s not a check valve.
Thinking more about it, I kinda doubt the line to the EGR control valve should have a check valve in it. So there should be an inline check valve somewhere in the line that goes through the firewall.
On my 1986 V12, albeit a saloon, there is a screwed barb on the manifold but it’s just a barb, and there are two external check valves, both in the engine compartment, one for the climate control (right side firewall) and one for the brake booster mounted on one of the cross-braces.
Kirbert
(Author of the Book, former owner of an '83 XJ-S H.E.)
14
