New to Jaguardom

That's a great project car you've got.

My opinion on the shifting problem is that you've pegged it: shift modulator. Either a vacuum leak or a bad modulator.

two more important parts resources:

www.jaguarheaven.com - a California scrap yard that has nearly everything
www.motorcarsltd.com - consistently lower prices than jagbits. They're also local to me here in Austin.

And this has proved helpful from time to time as well, though Kirby Palm is authoritative.
http://captainsodium.com/Private/XJS/jagcare3.pdf - by Gregory Andrachuk

Edited on 2010-05-02 0:36:19

Kent, you are quite right that overheating was the achilles heel of the Jag V12 XJ's. In S/Cal all cars used to come with 160 (summer) t/stats, it was only when emission controls were introduced that the 180/190 (winter)stats came to be standard fitment. The main reason for this was the hotter the engine could run the more efficient it was (leaner) . When I worked for a main dealer we recommended to owners that they should refit the 160's. This made a big difference right from the get-go. Another issue on the V12 was only having a temperature gauge on the right bank. On these models, the main fan was on that side and it worked whenever the engine was running. The left side had a separate electric fan which only worked "as required". The criteria was engine temperature as monitored by the temperature gauge on the right bank, if the electric fan did not operate OR, if the left thermostat did not open we had a very hot left bank and a normal right bank. this was why almost all failures were left banks usually dropping a valve seat without any apparent warning! We fitted many cars with an additional gauge on the left side to prevent this. Interestingly enough, we just had an 89 in for a purchase inspection, a very clean and well maintained example. On this, the owner had installed two large electric fans in place of the original set up, it was a good installation and worked so much better and gave more space at the front of the engine. (I still recommended he fit a second gauge, it can be fitted in the engine compartment, rather than wiring it into the dash somewhere. good luck.

Well, I tried 3 times to post a photo, but I am not clued into what magic it takes to get one posted within the post...

Edited on 2010-05-02 0:24:37

Edited on 2010-05-02 0:22:33

Edited on 2010-05-02 0:12:06

Edited on 2010-05-02 0:06:59

Welcome to Jaguardom - it's a great place to be!! (provided you take care of your car(s) as required). I have had (and still have) Jaguars. They are great cars! With a V-12 Jaguar, I have discovered that keeping engine cool is paramount to a long, happy life. Your first priority is to ensure that it does not run hot. I had the lower-temperature thermostats installed on my 1990 XJS and I just had the radiator removed, rodded out and flushed, and I put in a new fan clutch. Although my car did not run hot, per se, according to the temperature gauge, the needle would get to the top of the "N" sometimes while sitting in traffic in the summer with the A/C switched on. At that temperature, post-shut down heat buildup would put the needle north of the N, which can be detrimental to the engine seals and other components over time. With the radiator service work I just had performed, the needle rides a bit below the N while sitting in traffic, even with the A/C on. While driving, it is only halfway between the low mark and the bottom of the N. It made a HUGE difference and I highly recommend doing that to any XJS, regardless of the mileage. Mine only has 30,000 miles, so it's an age thing as much as a mileage thing.

Happy motoring!

Edited on 2010-03-27 13:30:18

1972 Stag!
He is well prepped mentally for any inevitable mechanical gremlins that arise in the Jag ...

D Lokun
90 XJ-S, etc.

Charles/ Carl--you can get the factory books here in the JCNA Shoppe and you will not beat the price--these are official not aftermarket! Take a look!

I just bought my first Jag too.
The parts guy at SB Jaguar told me to go to Jagbits.com for parts that are no longer available through Jaguar.
Theu have the Shop manuals for sale.

Hello Carl. Good luck with your project. This is my first login to the Jag forum and I'm simply amazed! The responses you received are fantastic. I admire and appreciate all of those who responded to you. I hope I do half as well when I post my first of many requests for help.

I have a 1991 XJS which I bought after it suffered an engine fire. I have replaced the affected wiring, hoses, etc and have it running. The engine will not idle and runs at about 1800-2000 RPM.

I checked the rotor button, and it has melted and has only one of the contact arms working. I picked up a new one today and hope to resume work on it this weekend.

When one of the coil wires is removed, the engine idles down better, but while driving, the car has very little power. It acts as if the timing is not quite right. The distributor was removed while the other work was being done on the injectors, wires, hoses, etc, and I haven't checked the timing yet .

What I really need is some knowledgeable direction from those who have exxperience with XJS's. I want to buy a good shop manual or other manuals which cover this auto and the 1988's. I also have a 1988 which has been sitting for awhile.

I haven't had any luck checking EBay and Borders books for specific manuals. I have found a Haynes manual listed for the 85-88's but have not bought it.

Any help and direction will be greatly appreciated. Hugo in Georgia.

Yes George, I did read them, but seeing if this vehicle will run is going to be my first priority. after that comes the driving part. If anyone wonders why i would buy a car without hearing it turn over... well I only paid 400 dollars for it. I figure it was a pretty good gamble

Carl just letting you know the priorities for that fault--did you read them--the first 2 are adjustment and fluid level!!!

Jeez George, what a ray of sunshine you are. The faint hope that the vacuum line popped off the modulator just whisped away into the sunset.
William, thanks for the instructions. I've basically cleared away most of the stuff on the top end of the engine for inspection and replacement, and will be testing for compression and oil pressure next week. So wish me luck and I'll post here to keep all informed. Again, thanks for all of the expressions of support and good wishes

Hello-Carl,-i-can-see-you-are-a-glutton-for-punishment-and-the-Stag-wasn't-enough-for-you.I-personally-like-the-XJS-V12,but,-a-28-year-old-one-could-be-a-challenge!.--Before-doing-too-much-work,-check-the,engine,get-it-running-the-simplest-way-possible,-you-have-oiled-the-bores,-so,check-that-the-oil-isn't-badly-contaminated-&-using-a-battery-charger,-and-with-the-plugs-out-turn-the-engine-over-until-you-get-an-oil-pressure-reading.-Now-you-can-do-a-compression-test,if-so-far-so-good,plugs-in-and-fire-it-up-You-can-now-let-it-run-until-hot-and-see-what-leaks-you-have-etc.-Also,you-can-check-fans,noises,gauges-gear-selection-etc.If-all-seems-reasonable-you-can-now-drive-it-for-a-few-days-for-testing-.Once-you-are-satisfied-there-are-no-major-problems-then-start-spending-money!--good-luck.

Carl do join a club--or become a member at large--in either case order the correct manuals--to make the case the symptoms you describe are (in priority) listed in the factory manual as 1-Fluid levels 2. manual control adjustment 3. Front band adjustment 4.converter failure 5. Front clutch worn 6. Oil tube broken (in pan) 7 Rear band locked on 7 primary valve sticking 8 Throttle valve sticking 9 1-2 valve sticking. So a good service of the trans and inspection of the tubes while the pan is off might solve this--then again!!! Good luck!

Thanks everyone for your comments. Owning a Stag has probably prepared me for the worst that could happen. I'm in California temporarily, but will be moving back to Portland OR. in June and will join the local Jag club then.
according to the LOLfG (little old lady from Gardena) right at 10 years ago the car was taken to Purrfect Jaguar in LA for a shifting problem (wouldn't shift from first to second) On the way home, the car started doing the same thing so they garaged it and never drove it again. Call me crazy...but that sounds a lot like the trans vacuum modulator. HMMM.

I second George's comment. However I would advise joining a local club since this automatically makes you a JCNA member. I say this because I help run our Concours and there have been members of JCNA that are not club affiliated that the Concours software has booted off the entrants roster because they are not club affiliated. In the years I have belonged to our club JANE we have been to most meetings a lots of events. The people are the nicest people I have ever met. My honey and I have make lifelong friends as a result of JANE. Last, no one will ever understand your love for your Jag like another Jag owner.

Welcome Carl and happy motoring--I would suggest you look in the shoppe here and order a proper factory service and parts manual. Over the years I have found they provide more information than Haynes (but not as many pictures). Good luck--By the way have you joined JCNA--members get a huge discount on everything!

Click the link below to "The BooK'. Tons and tons of good XJS info...stuff you'll never find in a regular shop manual.

Be advised that it paints a rather gloomy picture of the car...don't be put off by that.

Cheers
DD

Hi Carl

I think you're taking the right approach. Make sure new underhood fuel hoses are included in your replacement of all hoses.

Once you get it running make sure the cooling system is 100%. About the only thing that'll hurt a Jag V12 is overheating. The engine is darn near bullet proof otherwise.

Make sure the fuel tank isn't rusty, internally or externally.

Yes, it has a TH400 trans...but not exactly standard. The case is unique to Jaguar. The internals are standard GM fare except the torque converter which is designed to withstand 6500 rpm.

These are fantastic cars and a joy to own and drive once everything is sorted. However, just about every system of the car has quirks...which you can chip away at (and we can help with) as you progress thru process of returning her to the road. It might be easier if you have specific questions or concerns that can be addressed one at a time.

Cheers
DD