I've slowly been fixing all the bugs in the 87 XJSC I bought a couple of months ago.
So far I've repaired - Horn, would not sound. Traced to the fuse block in the engine compartment. Bad connection, also fixed the Aux cooling fan at the same time.
Replaced the Thermal Limiter Switch on the A/C and recharged with 134A.
Traced down wiring and now driving lights operate.
Replaced front and rear Brake pads. (Parking brake is fine).
Went from rear to front cleaning and used dielectric grease on all electrical connections.
Installed new battery
Repaired Dayton wire wheel where it was slowly leaking around spoke in rim.
Replaced all Lucas fuses with AGC equivalents. Taking into account the fuse rating differences between them.
Also replaced one of the Hi-beam headlight connectors (broken wire).
Repaired Cruise Control (Sealed the Bellows)

Now its time for the tune up. What I plan on replacing is

Spark Plugs with NGK, question I have about these, you have Standard, Platinum, and Iridium, Are Iridium's worth the extra cost?

HT Leads 8.0MM
Distributor (Dizzy) Cap and rotor. (will overhaul Dizzy according to Kirby Palms book)

All Vacume lines
All fuel lines with EFI hose
Fuel Filter
Radiator and heater hoses
All belts
New Anti Freeze
Oil Lube and Filter - Castrol Magnatec
Air Filters
thermostats

clean Injectors and replace seals and O rings
Compression Test and fuel pressure and radiator tests.
Clean radiator and oil cooler cooling fins

I'm trying to establish a service reference point for myself for future maintenance.
I think I have covered all I need, but the v12's are new to me. I'm hoping all you V12 owners can give suggestions on anything I might have missed.

The car actually runs like new, Temp runs about halfway between C and Normal, MPG is about 18 on the highway. I'm not in a rush to do the tune up because of this, just something I will feel better about. As soon as I finish this, I will be pulling in my 83 XJS - HE and get started on it.

 

I've spent a bit of time reading all posts about the V-12's to see areas where special care or attention was needed.
Took a few weeks gathering up all parts and supplies necessary for tune up.
I decided to do this in steps, instead of just tearing everything down at once.

Steps are -
1 - Change Fuel Filter in boot - Completed
2 - Change Oil and Filter - Completed
3 - Remove all vacuum lines and wires on top of motor and tag each for position.
4 - Remove Air Rails and hoses - Completed
5 - Remove Fuel Rail and Injectors - Completed
6 - Remove Distributor Cap and HT wires - Completed
7 - Cover and plug all open ports and using high pressure air, clean all dust and debris from valley area of motor. - Completed
8 - Remove Spark Plugs and check, all were light brown, no major carbon build up. Front plugs by A/C compressor, did not remove the compressor as mentioned, used a pass through 15mm socket and loosened with wrench, pushed old piece of fuel line on tip and finished turning out by hand. - Completed
9 - Compression Test - Compression according to ROM should be in the area of 220 psi. allowing 10% deviation. With injectors removed, compression was averaging 180 psi. Replaced injectors with old seals and compression came up to 205 psi average. Not perfect, but considering age of car and low milage (26543) acceptable - Completed
10 - Remove injectors from rail and pressure clean (use spare connector) - Completed
11 - Install new fuel line on injectors and rail, fuel feed lines from regulator and rail. - Completed
12 - Clean Air Rail tube and ports thru manifold - Completed
13 - Check and lubricate Distributor - Close to 11 degree movement, oiled center shaft - Completed

After these steps are all completed, will reverse steps, replacing hoses as I go Several different sizes will cut and fit as I work in that area.
I placed all nuts, washers etc.. in separate containers as I removed them and marked as to where they are used.

So far I've spent 4 hours, hopefully all goes well and will complete tune up today, then on to radiator cleaning, Vee belts, thermostats and hoses.

 

Well done.

That is the most sensible spproach to a "new to me" V12 I have heard in a very LONG time.

As Doug has said many times, do the Grazing method of catch up, and be at it forever, is so true.

What you are doing is exactly what I have always done, and never had reliability issues.

 

Absolutely good planning and execution. It will pay off in trouble
free pleasure, big time.


My choice would be standard NGK or any other top name. Fancy expensive, why???


Carl

 

Fancy expensive Why?? Cannot really answer that. I have an account at my local Orielly's and I get a discounted price on most items. Plus as big a job it is of changing plugs, figure it might be worth a little extra cost. Only time will tell. Plus, after starting this, I'm willing to bet this car has never had a tune up. Plugs were Champion RS9YC's, fuel line had tags dated 8-1986, injector lines were so brittle, you could snap them in two. Lucky I got started, it was a fire in waiting.

 

This test can vary for a number of reasons, and should be done with throttle wide open. The outright numbers are not so important as the balance between the cylinder. Your gauge may even read a little low.

I have pulled down my spare engine and ALL the valves had a buildup of carbon, and leaked when I filled the chamber with alcohol. This will cause low pumping pressure, and a wide variation between cylinders. Give it a good Italian tuneup when you're done, drive it like you sole it for a while.

BTW your approach to getting your XJS back up to snuff is a good un. Do it right and do it ONCE.

 

I really appreciate your thoughts on the way I try to do things. I guess I've always been methodical in the way I go about things. My dad always told me "When you think you know it all, You don't, If you do then your dead" and "There's nothing you cannot do if you read, study and try".

While changing all the fuel lines, I noticed that the throttle shaft linkage bushings were worn out. (Plastic) So I'm planning on machining out some new ones using Brass, simple to turn out, just a stepped bushing, should out last the plastic ones.

 

I did this, but I used Derin, it's what we used for input shaft bushes on our gas meter indexes and they have been in the field for 20-30 years.

 

Total time spent about 24 hours. Have everything back together. Re installed the fuel pump relay and let it pressure the system two times while checking for leaks. Did not find an so I installed the HT coil lead and cranked her over, took about 5 seconds, started a little rough, but smoothed out after another 5 seconds. Idle was up to about 1000 rpm, not sure if that's because it was cold. I cleaned the throttle bodies since they were off while I repaired the linkage, and with all the new vacuum lines, air pump lines and rails cleaned and injectors clean, it could be I will need to adjust the AAV. I turned it up right after I bought the car because the idle was low. Tomorrow after work, I have about 30 minutes left on it. I'm re routing the wires up out of the valley and need to replace carpet and tire in the boot. Will take it out for a test drive then and check for any needed adjustments. Will have four days off next week, so I will start on the radiator flush and heater hoses. My wife is ready for me to get this out of our shop so she can have the wrecker service move the 83 in for me to start on.

 

Warren, I would have used Delrin or similar but I had some 3/4" OD Bronze rod, (I said brass earlier, meant bronze) to turn the bushing with. It only took about 1 hour, took longer to set up the work piece in the lathe than it did to turn it.

 

Bronze will last forever.

 

About the only thing I would add to the tune up list is O2 sensors. IF they are original, new ones will work better and probably improve the mileage a bit. I like the NTK brand ones best. As a bonus, they seem to be smaller than others, which makes it easier to install them.

Jaguar later specified NGK BR7EF plugs for the V12. They don't need anything fancy.

 

Jagboi64, I used NGK TR5IX, do not know at this time if they were worth the extra cost, but hopefully so. As for the oxygen sensors, did not figure I really needed them, car was averaging close to 18mpg. Plus cost of +/- 200.00 for both of them.
I doubt if I gained much in the way of performance compared to the way it was already running, but seems to run slightly smoother. Main thing was the fuel lines and assorted hoses, they were pretty much dried and hardened to the point it was just a matter of time before something major would have happened. (Fire). Injector seals were hardened and could have been part of not running really smooth. There was no bad carbon build up in air rails, throttle bodies, and plugs were burned normal (light brown).
Mainly, I gained some experience on the V12, established a maintenance point for my records, figured out a way to change the plugs on 1A & 1B without removing the A/C Compressor. Most of the time was spent on cleaning the injectors, changing out the fuel lines on the supply lines and fuel rail, I managed to save and reuse all the pintle caps.
This week, I plan on reading and studying up on the radiator refilling and bleeding, seems like that from what I've read is the main thing on cooling system maintenance.

 

I usually buy things like plugs, O2 sensors etc on rockauto.com. Cheapest place I have found so far, and fast shipping.

Filling the radiator isn't too bad, just have the front of the car raised and fill it slowly to let it burp. Fill through the crossover tube, not the tank on the side. I usually fill it up to about 3-4" below the filler neck and then start the car and let it warm up. Make sure the upper coolant hoses get warm and I let the thermostats open. The I let it cool, check the levels and add more if necessary. Might take a few heat cycles to get it really full.

Other big cooling problem with these cars is they tend to collect debris between the radiator and condenser. It's amazing how much can be blocked off.

 

WOW!! Not sure exactly what made such an improvement in the way it runs now, but it's almost like a different car. Had to adjust the AAV valve to lower the idle RPM's. It does run noticeably smoother and seems to have more power, barely giving any throttle and the back tires chirp. At any rate, it was worth the time and money spent.

 

Absolutely, and I am not surprised. Once these cars are right, and I mean 100% right - not just going OK - they are a completely different animal. Really well done, and an example to us all.
Greg