[Sean's Jaguar XJS Tech Pages]
XJS V-12 Vacuum Routeing diagrams

Last modified 2005 APR 07 04:40:08 GMT

I've been noticing a trend on the Jag-Lovers lists of people requesting vacuum routeing information because they cannot read the tags under their bonnet, or in some cases, the tags don't agree with the general scheme of things (possibly Lucas tags, Marelli ignition). In any event, I thought it was high time someone went and produced workable reproductions of the underbonnet vacuum diagrams for various years and markets.

IF YOU HAVE A CAR FROM ANOTHER MARKET BUT FOR WHICH THE YEAR IS LISTED HERE I still want to hear from you -- I want to document which labels existed on which years in *ALL* markets. If the stickers on your car appear on this list, but the market and/or year isn't listed for your car, I need to know.

I am interested in receiving non-lossy compressed images of the underbonnet diagrams - PC byte ordered TIFF images would be best (versus JPG, which is a lossy format), and they should be GREYSCALE (not RGB - these stickers aren't colour, and to email them as colour images is to make them THREE times as large as they need to be). I'd like them shot as straight-on as possible to reduce distortion, though when photographing them, you should take special care that your flash doesn't glare the image (use a flash diffuser or use bright ambient light and cover the flash, etc). I'll perform image touchup, (I'm going so far as to re-type all the text on the labels), though if anything on the image is difficult to read, I'd appreciate that the accompanying email identify what you can make out in person (actually, if you've got a really crappy label, I'm not interested, unless nobody else can provide that same label).

IMPORTANT! Email me the information about your car and the diagram info (see below) BEFORE you take the shots and email them to me. Doing so will save you time, because I may have already received such images from someone else, but not have posted them here just yet, and besides, I do not wish to be deluged with redundant images, and a lot of unneccessary attachments. When people provide me with label information, I'll want the following:

Neither your serial number or VIN will be published - they will be used strictly by me to organize the data and to weed out possible diagram conflicts should any arise.

Just in case I wasn't clear -- DO NOT SEND ME ATTACHMENTS SHOWING YOUR CAR PLUMBING OR LABEL unless you've first sent me the description (as per the above) and I've indicated that this is welcome. I get an UNBELIEVEABLE amount of email, often containing series of pictures people want me to explain, or copies of pages from peoples workshop manuals (which I already own, thank you), and which I simply don't have the time for. I cannot answer plumbing questions for cars which differ from the two which I own (and coincidentally, have their diagrams posted here, so there should be no need to ask).

The images provided here are intended to be able to be printed crisply on a plain black and white laser printer (and as a result, will print crisp on any other printer as well). I do not as of yet have a list of the various Jaguar part numbers for the labels, which should appear on the label themselves (as an example "EBC 2682").

As this resource develops, if you see a diagram identified for your year and market, but which differs from what you have (in actual plumbing, not just the sticker you've got), please notify me, and I'll do my best to investigate why.

These diagrams are being collected only for the fuel injected V-12 engine - if you have a routeing source for carbureated E-type and early XJ-12 sedans, I'd be interested in collecting them here, but if you don't see them here, please don't request them - I have no source, and no way to first-hand confirm the accurracy of the diagrams (for starters, I have extensive XJ-S printed service documentation, but nothing on other models).

Sometime later (when I get the time -- and I really don't have the time for this project to begin with, but it obviously needs to happen), I hope to produce a consolodated document containing the various vacuum routeing diagrams with colour tracers for the different vacuum lines, documenting the COMPLETE vacuum routeing under the bonnet (charcoal cannister, ECU, fuel pressure regulators, etc), as a PDF. This is some time away, but it is a goal I have established, and with the help of owners of various market XJ-S', one that can be met.

Model Year(s) sighted Market Description Sticker Part Number
1985 & 1988 USA Vacuum Routeing Diagram EAC 5990
1985 USA Vacuum Routeing Diagram (charcoal, speed, crossover) EAC 5991
1985, 1987, 1986 & 1988 USA Vacuum Routeing Diagram (dump valve, dist advance) EAC 5992
1986, 1987 USA Vacuum Routeing Diagram (identical to EAC 5990 except for omission of fuel pressure regulator, which is present, but simply not shown) EAC 8547
1986, 1987, 1988, 1989-LUCAS USA Vacuum Routeing Diagram (charcoal, speed. crossover, fuel pressure) EAC 9485
1989-LUCAS USA Vacuum Routeing Diagram (Note lack of brake servo -- ABS car) EBC 2518
1989-LUCAS USA Vacuum Routeing Diagram EBC 1347
(coming soon)
1990 USA Vacuum Routeing Diagram (charcoal, speed, crossover, fuel pressure) EBC 2681
1990 USA Vacuum Routeing Diagram EBC 2682


Sean B. Straw
Post Box 751224
Petaluma, CA 94975-1224 USA

EMail to: Sean.Straw+Jaguar@mail.professional.org

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