Interesting, I didn't see as much vacuum stuff on the left side as the right side, but when I was looking for the purpose of getting pictures for this post I kind of got distracted by that filter on the distributor lol

 

haha... There is lots to be distracted by. Lots, but once/as one gets more familiar with the things going on, it's actually not so bad under there... I just read your profile and the comment about the RX-8 and Jag comparison in being a money pit and,,,, well, I don't know much about the Mazda, but unless you are trying to make the XJS perfect, perfect, it's actually not so bad to maintain cost wise. At the same time as values go up for the XJS (and I'm sure they are/will) that could change...

And Brother. I just want to say that I am maybe 3 yrs in with my XJS, and I could be MISTAKEN in identifying any O them things I tried to name. For instance, on the Marelli car (my 1990) there is no vac advance for the distributor. In that, the other end of that hose with the small filter that goes to the distributor MAY end up in a different place on yours than mine. I just kind of enjoy trying to guess,,, and help

 

I don't think I am trying to make this car perfect, just good enough to drive around, once I get the mechanicals sorted out I can work on the cosmetics here and there. Already looked into replacing most of the leather - shouldnt be too bad. I still need to look into seals - door seals, sunroof seals, stuff like that. The floor isnt rusted out and the car was kept outside under some trees so I'm thinking at the moment it doesnt leak but they still need replaced. The headliner is horrifying lol and almost 40 year old carpet - is 40 year old carpet. I think all in all it'll be fun though.

Far as the mazda being a money pit lol these rotary engines are very cool but at the same time kind of fragile and finnicky, and its turbocharged on top of that so that adds a whole host of headaches. Neat cars though.

Even if you're not spot on about your guesses I appreciate all the input, sometimes even a wrong guess can end up pointing you in the right direction.

 

Okie doke - picture #5 has been determined as the solenoid which engages the dump valve. Whats fascinating about this - I think we determined the disc shaped thing to be the dump valve which is made in the usa, and this solenoid that engages it made in japan, but is still an authentic jag part. Found a post somewhere else about it.

 

Apparently Picture #4 is a vacuum regulator responsible for idle stuff in the first 45 seconds after starting. Right now both lines from it go to the dump valve with a T in the top line that goes up into the middle where it is currently capped so not sure where it use to go. The post I'm reading about this from is kind of difficult to follow so I will have to read it a few more times to see if I can get a sense for whether this is plumbed correctly and where that T is suppose to really go. Though it sounds like the T is suppose to go to the vacuum advance.

 

The wires in right half of picture #3 appear to go to some relays mounted on the radiator. Idle relays someone said? But where do they plug in? The wires on the left side of that picture I traced back to a cluster of wires on the back side but I lost track of them around the middle so not sure where they end up.

 

Now the wires from the second photo jay you were spot on about - however, those particular wires actually daisy chain off of the wires that are already plugged into those blue wires. So I dont know whats up with that. Also just to keep the mystery machine rolling I found some more things not plugged into anything - will post pictures here in a sec

 

these two plugs that go nowhere are still on the right side. I found them just tucked under that support

now this wire here going to that ignition module. The black wire just soldered to the white one doesn't look very factory. Is that the way that it should be?

 

IIRC this is a shielded wire from factory, sending ignition pulse signal all the way to the ECU, injectors don't fire without it. These are notorious for shorting the actual wire to the outer shielding, someone probably replaced a section of it with normal wire and the black wire might be connected to the shielding on the good section further back.

Most of the other stuff in your first post (the vacuum solenoids, valves etc) seem to be a part of the vac advance delay timer circuit, which can be removed. The diagram Doug posted shows this circuit and this thread has a link to a video showing how to remove it: https://www.jaguarforums.com/forum/x...-timer-247364/

 

That video was fantastic, thank you for that.

 

Sardonicus, do you have the S57 wiring guide? It is very useful and will answer many questions.

If not, PM me your email address and I will send it to you.

Cheers
DD

 

Got your email - thank you for that. Super helpful.

 

So after following the instructions on that video for removing a bunch of these components and several hours tracking down other vacuum leaks and one ignition problem that was just moronic, the car now happily idles at around 900 give or take. The ignition problem was someone deciding rather than to put a blade connector on one of the wires for one of the coils - they just stuck the wire down into the slot and hoped for the best. Big shocker with me digging around for vacuum leaks I bumped it and it wouldnt start - kinda surprised it started sitting like that at all.

 

Well found!

 

I believe picture #2 in post 28 is part of the wiring for the cruise control system... Looks incomplete, call me captain obvious... Much of the wiring for the CC is a mix of yellow, black and white wires and a mix of these colors in stripe.

 

It would not surprise me even a little to find more cruise control components missing. I actually have a very throttle cable looking cable stuffed in a bracket that has been cut. I am assuming it belongs to the cruise control too.