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Congrats to you, too, as I also purchased a '92 5.3 black/black coupe "mechanic's special" late last year and have been slowly getting it back into shape again, using guidance both on here and the original Jag forum. I guess our Jags are kinda the "stepchild" of the V-12s, being the first and only MY of the face-lift 5.3s.
My latest concern has been not finding an driver's handbook for the car. which I understand is over 300 pages long. The only one I have even been able to find is on Ebay and that ridiculous owner now has the price for same raised up to $800.00! Anyway, I DO have the '92 supp. brochure (66 ps.) from Jag, and that helps a lot in regard to the "updates".
Great choice of car. Providing you go through all that needs doing methodically and can do the work yourself, the parts are not idiotically expensive. The rear axle needs to come out to do the brakes, and while you are there do the lot: callipers, discs, radius arm bushes, change diff oil. If you search on here for XJS handbrake modification, there is a downloadable pdf that explains in detail how the HB works and how to greatly improve it if you are so inclined.
The Great Palm's book explains in detail how to set the throttle plates properly (basically use the throttle stop screws and a feeler gauge). Once the throttles plates are set, if the high idle remains, you have a stuck AAV, or the tickover screw on the AAV too far open, or a leak or all of the above.
The most probably cause of the vague steering is also dealt with in detail in the Palm book - being the rack bushes.
Depending upon your own requirements and inclinations, there is a great deal to be said for going through the whole car on the assumption that it has been poorly maintained, fixing all the known things that arise with the car under those circumstances, and after a bit of work you will have a reliable car. My list would include:
Fuel system complete clean
Injector flexible pipes changed, injector loom changed
On your car the Marelli dizzy cap and arm need careful inspection, changing if needed, and the amplifier looms also changing if they are cooked.
Thermostats change
100% coolant pipe change
Remove rad and clean out the fins and the crud in the oil rad and a/c condenser fins
Check front discs and calipers (also very carefully test the Antilock brake system which can go haywire, a search here will show how Orangeblossom rebuilt his actuator after a couple of scares)
Check balljoints and front suspension rubber bushes carefully
Clean up all engine bay earths very carefully, particularly the one from the engine via the subframe to the LHS lower chassis rail.
Test aircon carefully for full function, the system on your car is good, but various water valves and other bits can jam, vac pipes get leaky etc.
Seems a lot, but all doable with patience and dedication! And you will end up with a wonderful Grand Tourer.
Greg
On that list, I'm currently on the "thermostat" change process for Superblack. Although she doesn't seem to have any problems in that regard (or as to her running temp in general), I've decided it's a prudent idea to swap the thermos out now for those "FailSafe" ones that Autozone sells, designed to always fail in the OPEN position rather than closed, should that unfortunate event happen in the future. Problem is that b/c there are two thermostats (one for each bank) and yet only one temp gauge monitor (i.e. on one bank), if the thermo on the "silent' bank should fail closed I would fear the coolant temp might possibly go up considerably in that bank before it becomes evident on the dash gauge, possibly leading to the horrible dropped valves scenario.
This one is black with tan interior. I'll post some better photos when I get her out of the garage .
I think you're right about the front bushes - I'll have a good look up front in the coming week.
Mike
After I saw that she was black and has a couple of the same issues as my '92, I wondered if maybe I bought this same car a few months ago as my Superblack (which, btw, was originally a PA car). (?) But then I quickly saw that she is a convertible with doeskin interior, whereas Superblack is a black/black coupe. Still, it kinda freaked me out to read/see that .. !
Made some progress yesterday. I replaced that broken hose with a better quality rubber generic hose and voila, erratic idle gone. No she warms up and sits at about 1100 rpms. Still seems too high but I'll have to do some research on this as well as further inspect the engine hoses. I did adjust the idle bolt in the AAV and did manage to reduce the idle just a little. I suspect the AAV, while now moving, is still needing attention (as superchargedtr6 menitoned earlier). So I'll have to figure out a rebuild or replacement...
Yesterday I managed to start on the rear brakes. Not as bad as I thought it was going to be, although I was hoping I wouldn't have to cut the exhaust. There doesn't appear to be a way to weave the rear exhaust outta there without cutting though...
Rear brakes are in *bad* shape LOL... have new ones on order.
Can't get that darned thing out LOL
Very poor condtion
Hmmm per the factory service manual literature (do you have a copy of it, either hardcopy or on CD?) should not be necessary to mess with the exhaust system to r/r the rotors/discs. Just follow the steps in the manual on how to maneuver things out/back in.
On the large end of the radius arm bush, where it attached to the body is cup shaped. It fits over a mirrored cup shape welded to the body. Get a cold chisel and place the sharp end against the just-perceptible join at the top of the bush inner, where the cups fit together. What this REALLY HARD with a lump hammer. It will come off. The bush outers are very hard to remove from the arms. If you do not have a press and a tool of the right size, and the bush outer only comes out on one side there is a shoulder on the other but tiny, either buy a new arm with the bushes already in it, or CAREFULLY cut through the bush outer steel with a hacksaw from the inside outwards, but STOP before you cut the actual arm outer. This will be sufficient to release the grip of the bush outer and you can then get it out.
The small end bush must only be tightened once the weight of the car is back on the wheels.
Greg
I have this task coming up very soon, as I discovered only AFTER buying Superblack on Ebay that she has a couple of major rusted areas underneath on the rear passenger side, which seems to have come from the inside out. They tell me this area is very prone to rust, and in fact I have ordered from one of the U.K. vendors a patch kit (made of thick stainless steel plating - 2 pieces) for the rusted area to be welded into place when the time comes, made just for that purpose. I don't understand though why it seems so many owners insist on buying the radius arm bearings and taking upon themselves the PITA task of pressing them into the arms on their own. One of our usual Jag vendors sells a new arm with both bearings already installed for approximately $100.00 U.S. In my case, a new bearing cup will need to be installed, although fortunately the arm and bearings seem O.K.. However, they are riveted into the suspension member, not welded. Hopefully whomever does the welding work for me has the knowledge and tools do handle the riveting as well.
Last edited by AttyDallas; 05-25-2020 at 12:21 AM.
If you remove the 3 bolts/nuts that secure the rack to the chassis, but leave the tie rods connected, you can lower the rack enough to get a better look at exactly where it is leaking. A hose leak can sometimes look like a tower seal leak.
BTW, if you have the OEM rubber bushings at those three points, you'll want to replace them with polyurethane. Improves steering response, and lasts significantly longer.
The main issue on Superblack when I bought her was the PO reported a major p.s. leak, but didn't know (or say?) where. Turned out after getting in there (after dropping the p.s. rack) it was the low pressure hose had split. I thought it kind of odd that the low pressure would give up the ghost before the high pressure hose, but it did. In good prudence, though, I r/red both hoses. When you do the job though be aware that both hoses are encased in a "heat shield sleeve". Knowing that mine were likely coming apart after 28+ years and, IIRC, new one are N.L.A., I was able to source some generic ones at one of the usual large chain auto parts stores and they work very well. The alternative plan of action was that I would wrap them with some of that high heat tape from the same store, which you cut to length and then wrap around the hose in one big piece. Be sure you follow the instructions on bleeding the p.s. fluid system when you are done (they were printed right on the packaging of my aftermarket hoses). Oh, btw, one of the hoses - despite being supposedly made to "OEM specifications" - was a bit too long and came with an unneeded connector on one end. I cut off the connector and extra length and attached the hose using the OEM hose clamp (i.e. worm gear clamp).
Last edited by AttyDallas; 05-25-2020 at 01:12 AM.
05-24-2020, 11:12 PM
Anyway, I DO have the '92 supp. brochure (66 ps.) from Jag, and that helps a lot in regard to the "updates".
In my case, a new bearing cup will need to be installed, although fortunately the arm and bearings seem O.K.. However, they are riveted into the suspension member, not welded. Hopefully whomever does the welding work for me has the knowledge and tools do handle the riveting as well. 
I thought it kind of odd that the low pressure would give up the ghost before the high pressure hose, but it did. In good prudence, though, I r/red both hoses. When you do the job though be aware that both hoses are encased in a "heat shield sleeve". Knowing that mine were likely coming apart after 28+ years and, IIRC, new one are N.L.A., I was able to source some generic ones at one of the usual large chain auto parts stores and they work very well. The alternative plan of action was that I would wrap them with some of that high heat tape from the same store, which you cut to length and then wrap around the hose in one big piece. Be sure you follow the instructions on bleeding the p.s. fluid system when you are done (they were printed right on the packaging of my aftermarket hoses). Oh, btw, one of the hoses - despite being supposedly made to "OEM specifications" - was a bit too long and came with an unneeded connector on one end. I cut off the connector and extra length and attached the hose using the OEM hose clamp (i.e. worm gear clamp).
