1992 Jaguar XJR-S
Discussion
I think the time of thinking of these as "old mans cars" is long gone. Now they are just unique, distinctive, and interesting. Of course they were mostly driven by old men new though, who else had £45k to spend on a car in 1992 except old white men?
Edited by dme123 on Wednesday 9th November 22:30
I've finally found the time to investigate the radio issues in depth. It turns out that the ignition switched 12V supply never switched on. To "fix" this issue someone has at some point just joined the permanent 12V feed to the switched feed with a scotch block so the radio will power up. Downside of this, as mentioned, is that it keeps blowing the little 5 amp fuse for the radio memory circuit. As a temporary fix I admit that I put in a bigger fuse. We'll come back to this.
After some investigation of the wiring diagram it turns out that the switched 12V feed to the radio comes (inexplicably) through the heated seat relay. Heated seats don't work, although they did work one time I tested it. Ah, yes, that would be because the common output from the heated seat relay to the radio and the seat heater control modules was getting +12V from the scotch blocked connection at the radio loom! No wonder those fuses didn't last long.
Anyway that relay is dead. It's a fairly common 30amp 5 pin relay commonly used as a fuel pump relay, with a common output rather than a switchover output so I should be able to pick one up tomorrow. Oh and one final finding was that the amplifier switch-on output from the head unit had been inexplicably wired to the lighting control wire on the cars loom.
The more time I spend poking around under the dash and in the innards of this car the more I appreciate how far things have come in terms of the quality of engineering in automotive electronics.
After some investigation of the wiring diagram it turns out that the switched 12V feed to the radio comes (inexplicably) through the heated seat relay. Heated seats don't work, although they did work one time I tested it. Ah, yes, that would be because the common output from the heated seat relay to the radio and the seat heater control modules was getting +12V from the scotch blocked connection at the radio loom! No wonder those fuses didn't last long.
Anyway that relay is dead. It's a fairly common 30amp 5 pin relay commonly used as a fuel pump relay, with a common output rather than a switchover output so I should be able to pick one up tomorrow. Oh and one final finding was that the amplifier switch-on output from the head unit had been inexplicably wired to the lighting control wire on the cars loom.
The more time I spend poking around under the dash and in the innards of this car the more I appreciate how far things have come in terms of the quality of engineering in automotive electronics.
The only "modification" was the splicing together of battery and ignition switched 12V feeds on the audio loom. It was Jaguars clever idea to run the switched circuit for the radio through the seat heater circuit. Only the top spec XJS had seat heaters, but the wiring diagram only shows it being run through the seat heater relay so I think it would have been more sensible to call it "ignition switched circuit relay 2" or something. To be fair without serious effort to diagnose I can see why you'd just end up pinching power off the permanent 12V feed!
Finding a relay over the counter is harder than I'd hoped, so I'll order one from the internet now.
Finding a relay over the counter is harder than I'd hoped, so I'll order one from the internet now.
Edited by dme123 on Friday 25th November 22:10
Radio is working, heated seats working! I *think* the base but not back of the drivers seat is heated but they are so tepid compared to modern heated seats it's hard to be sure.
All is not well where the radio is concerned, there is no sound from the back left speaker at all and it generally sounds a bit rubbish. I took off one of the door cars to look at the speaker and this is revealed
I need to take out one of the rears to see if they are the same size, but I think some new speakers need to be ordered!
All is not well where the radio is concerned, there is no sound from the back left speaker at all and it generally sounds a bit rubbish. I took off one of the door cars to look at the speaker and this is revealed
I need to take out one of the rears to see if they are the same size, but I think some new speakers need to be ordered!
In the process of replacing the speakers I discovered that the bodger has been there before too. The NSR speaker was held in with a single screw and not connected, explaining it's lack of function.
I've also ordered the two coils and link lead to convert the car to dual coil, as per a 1999 TSB from Jaguar. That'll be boxing day sorted.
ETA - the bodger didn't just confine themselves to the radio. Looking at the coil there is only one bolt holding it down, and then upon removing the trim to look at the rear speaker I discover seat bolts done up finger tight, and a speaker totally disconnected and held in with only one of three screws.
I then notice that the oil pressure switch (separate from the oil pressure sender) has a broken connector, which seems odd as the oil pressure warning light isn't lit. Ah, it doesn't even illuminate with the ignition on but engine stopped. I suspect someone has removed the bulb rather than replace the £3 oil pressure switch.
Then, to cap it off, I notice that the crankcase breather that should connect with a pipe to both airboxes actually vents to atmosphere. Needless to say the JaguarSport XJR-S specific crosspipe is missing.
What the f
k possesses these animals.
I've also ordered the two coils and link lead to convert the car to dual coil, as per a 1999 TSB from Jaguar. That'll be boxing day sorted.
ETA - the bodger didn't just confine themselves to the radio. Looking at the coil there is only one bolt holding it down, and then upon removing the trim to look at the rear speaker I discover seat bolts done up finger tight, and a speaker totally disconnected and held in with only one of three screws.
I then notice that the oil pressure switch (separate from the oil pressure sender) has a broken connector, which seems odd as the oil pressure warning light isn't lit. Ah, it doesn't even illuminate with the ignition on but engine stopped. I suspect someone has removed the bulb rather than replace the £3 oil pressure switch.
Then, to cap it off, I notice that the crankcase breather that should connect with a pipe to both airboxes actually vents to atmosphere. Needless to say the JaguarSport XJR-S specific crosspipe is missing.
What the f
k possesses these animals.Edited by dme123 on Saturday 17th December 14:46
craigjm said:
Based on that I would be doing a massively in depth service of the engine. A neglected V12 is an expensive beast when it finally spits the dummy
Yes I've come to the same conclusion. I'm going to go over every inch of it. I've been busy on David Manners today ordering bits. The problem is I cannot know if one shaved ape has just buggered up two or three things over the last 24 years, or if it's been subjected to a prolonged period of abuse at the hands of said shaved ape. FWIW the paperwork with the car suggests previous owners have not been shy with their wallets, but that's no guarantee of the quality of work whatsoever.
I've had a very productive boxing day afternoon with the car. The car came with a 2nd ignition amplifier which I've now "reconditioned" with new components and fitted to the car, the original can live in the boot as a spare. The LHS headlight didn't work on full beam so I went to change the bulb and found the spring clip was missing. Removed the headlamp unit (fiddly job) to see if the spring was in the cavity and change the bulb, but no joy. It stays in place pretty firmly from the rubber boot but I'll have to try and find a spring clip from somewhere. It gave me an opportunity to clean out the grime from the cavity so I took the LHS one out next to do the same.
The bulb was fine, it was the fuse for the LHS full beam that had gone. I've replaced both bulbs with uprated ones anyway. Sadly the dual coil conversion parts from David Manners have not arrived yet. My friend is dropping round tomorrow with his borescope so I can have a look at the insides of the engine, out of idle curiosity.
The bulb was fine, it was the fuse for the LHS full beam that had gone. I've replaced both bulbs with uprated ones anyway. Sadly the dual coil conversion parts from David Manners have not arrived yet. My friend is dropping round tomorrow with his borescope so I can have a look at the insides of the engine, out of idle curiosity.
dme123 said:
My friend is dropping round tomorrow with his borescope so I can have a look at the insides of the engine, out of idle curiosity.
Beats watching Christmas telly.Something truly appealing about cars like this, which seem to span the days of cars being simple beasts pre 80s, to the complex computerbeasts of the 90s onwards.
DaveCWK said:
Random question - Do any of the 6.0 Zytek owners in this thread know how the ECU senses crank/cam position? Does it have a trigger wheel on the crank pulley?
My XJS hasn't moved in 5 months now. This thread is useful motivation to try & find the time!
Hall sensors in the distributor I believe - it's a modified Lucas one rather than the later Marelli. The gearbox bellhousing lacks the fitting for the crank position sensor the Marelli system uses. I will check the docs to confirm this.My XJS hasn't moved in 5 months now. This thread is useful motivation to try & find the time!
Yep, gets both sync and engine speed from the distributor. What model XJS do you have?
Edited by dme123 on Tuesday 27th December 14:10
dme123 said:
Hall sensors in the distributor I believe - it's a modified Lucas one rather than the later Marelli. The gearbox bellhousing lacks the fitting for the crank position sensor the Marelli system uses. I will check the docs to confirm this.
Yep, gets both sync and engine speed from the distributor. What model XJS do you have?
Thanks dme. Yep, gets both sync and engine speed from the distributor. What model XJS do you have?
Edited by dme123 on Tuesday 27th December 14:10
I have a 1989 Marelli pre-cat with 12.5-1 compression. I'd quite like to junk all the standard engine control & go aftermarket. Currently thinking Megasquirt, with 2x Ford EDIS 6 cylinder modules for ignition, but that requires a 36 tooth crank wheel & sensors. The Marelli OEM pickup is I believe a 3 tooth on the bell housing. I'm not sure how compatible this is with other aftermarket options.
I'll have to make a thread when I eventually get round to doing something!
craigjm said:
If you're going to change the ECU Emerald works better with that setup than megasquirt and allows you to have three maps. That's the route I'm taking when the car is back.
That is interesting. A friend of mine with MS2 reckons that with OMEX and Emerald MS will do all of that but for a fraction of the cost. I have always been dubious but on paper it "almost" seems to be the case when I was looking at putting an ECU into THISIt was running Bosch KE-Jetronic with an MF-II 5th Injector which TBH was at its limits. I was going to fit either the BoostMonkeys ECU (read MS2 in a KE-Jetronic casing and connectors all being the same) or the Emerald with the following things wanted:
-Boost control via a solenoid
-A few outputs which I could hopefully do via temperature control including:
-Chargecooler pump control (I was running a Pace chargecooler)
-Engine fans
-Knock control if possible.
It seems however you are quite switched on in the ECU world
.Just found the thread
:http://retrorides.proboards.com/thread/185447/ecu-...
Back on track I do love an XJS and wonder "what if". It's time I had bigger cojones!
Edited by SebringMan on Wednesday 28th December 09:55
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