Good stuff as usual Grant. Added all these to my Google Drive
https://drive.google.com/drive/folde...5-?usp=sharing

 

That fuel pressure is correct; 2.5 bar is 36 psi, minus manifold pressure. Running with 16-17” vacuum is about 28 psi- if you have a “chugging “ idle, vacuum is going to be low, so fuel pressure will be closer to 36 psi.
Probably start be pulling either injector connectors (safe) or shorting plug wires (not safe) to see if all cylinders are firing. Probably a number of stuck injectors. Check centrifugal advance to make sure it isn’t seized, and vacuum advance unit for leaks; a stable idle requires the vacuum advance to be functional. Also essential is that the vacuum advance plumbing is correct,there is a vacuum reducer that limits vac to the distributor to 11” unless the ported signal exceeds that. Once all that is verified check the ignition timing, should be around zero (TDC) with vacuum disconnected at low idle rpm and 18 degrees at 3000rpm with vacuum disconnected.

 

Beartooth,

I stand corrected. You have a power seat but its just the seat back incline angle. Converting over a manual seats car to a heated seats and power seat car is a job far beyond me.

 

Man, many thanks for the PDF dump! I've also downloaded the XJ-S help book - that definitely helps too. I went into the distributor today. The only problem I found is the rotor carrier retainer is apparently broken, because the shaft pulls up with the rotor. The advance diaphragm works when you suck on the line (bleeds down slowly, which is apparently normal), and the mechanical advance doesn't seem sticky. The cap has a crack in the side that's been epoxied over, and the flash shield was also repaired, and is still missing a small piece or two. Also, a couple screws missing there. And, it was kind of oily inside, so maybe it's got some sealing issues. I might play with timing a bit and see if that does anything, but it sounded from what the PO said like it had been running ok the summer/fall before I got it, sat all winter, and something happened there. Maybe the injectors are half plugged up. It's good to know the fuel pressure is where it should be - as poorly as it's idling, I doubt it's able to pull more than 10" of vacuum or so. I'll have to look for big vacuum leaks again and dig through some of the PDFs for some nuggets. It would really help to get it inside at this point...

Yeah, I noticed that earlier. I haven't seen it do that with other sites; obviously it's mostly car stuff and nothing too embarrassing. I love the "Pasha" (as Porsche calls it) interior, and hopefully the 931 will be fully restored some day with that same interior. It is really polarizing - as tends to be the case when zee tchermans decide to have a bit of fun. I do have a more wild paint scheme in mind; silver(ish) colors were never my thing.

 

I was mildly disappointed not to find any pics of nekkid women, all i got was pics of cluster gears. LOL

I am really surprised that Porsche interior was factory, i got queasy (seriously) just looking at the pic for a short time, that pattern doesn't do well with my eyes.

Good luck with your projects. I can't offer any help on the motor repair, but I can on motor removal and front suspension rebuild, as i just went through that a year ago. If you take the motor out, getting the exhaust off is the nightmare, the cats are in the way of all the nuts/bolts you need to disconnect. A lift really helps, there.

Heated seats would be real nice in MT, I lived there (Helena/Bozeman) from 1970-1980, before was had heated seats...

Doug

 

Thanks Brad and others, I try.

Most of that was actually done prior to the Internet and the associate "stuff" it contains. Pen and paper were awesome. and screwing things up, then sorting that was a HUGE leaning curve. The advantages of being a Fossil, you HAD to think, you had to work out what was going on, there were NO shops, and besides that, NO money to spend in them.
Finding a shop anywhere today, GOOD LUCK, so if YOU are not able, dont want to, whatever, work on your classic, move the beast on, as it will never be as it should.

As I have mentioned a few times, in 2014, we took time off from life, and drove the '85 XJS around the Aussie Coast road, with many inland deviations, to a total of 25000kms in 18 months, and averaged 11.2L/100km fuel usage. The fuel thing, who cares, if its hungry, feed it, life's too damn short for that concern.

Now I learned recently, the bloody Hemi had 16 spark plugs for the 8 cylinders, Bugga, this will be fun. Must fill the beer fridge.

 

Man, I can't imagine trying to figure this stuff out in the pre-internet days! I seem to be able to figure things out sooner or later - usually with some internet searches and back and forth - but back when, you had to either be a genius or spend money (sometimes a lot) to get service manuals, and then you didn't have all the workarounds for doing a job without a special tool or jig and/or the tricks people find to make it easier.

I love heated seats up here! Both my Mercedes have them (the SEL even has them in the back seat!), and I put them in my truck, because even plugged in for hours (which you need to when it's -20F), you're at least five miles down the road before you get any heat (and almost ten minutes, because nothing's worse for an old-school diesel than putting the hammer down so you're up to 70+ in thirty seconds like most people do). Anyway, it looks like the seat mounts are the same (fingers crossed - I haven't confirmed yet), so *all* I need to do is get power to some switches and figure out what wire goes where. To do that, I plan to run a fused wire from the battery to a relay that's only powered when the ignition is on (or better yet, the engine is running) so the heaters can't run down the battery. I picked up a fan to hopefully fit at the junk yard this week, and while I was there I looked at the switch gear on a 90's Gran Marquis - that may work, although it'd be a little funky because they have height adjustment, but the lumbar is pneumatic. Also, no seat heat there... Be nice to find a car with the same adjustments as the "new" seats (front-back, recline, lumber, and seat heat), but anything with a memory seat or that works on relays (as my Mercedes do) is out. It could be a PITA even with plain switches, so I'm not going to add to the hassle. Also, seat memory has got to be one of the most overrated features ever. It's only on high-end cars that are typically driven exclusively by one bloke. Anyway, that might be one of my wild hares, but if it works out, I'm thinking it'll be a nice upgrade, especially with seats that are starting to fall apart like mine...

 

If you take a photo of the wiring plugs for the seat, I MIGHT be able to tell what some of the wires control, as I had to work out how to power a 1995 seat the other day that was out of the car.

Paul

 

Mildly disappointed??

 

Two things:

1. While it is very possible, even desirable, to save money getting junk yard parts for a lot of things the fan is not one of them IMO. Too much to go wrong with very expensive results.
Spend the few extra bucks and get a new one from Welsh, SNG Barrett, etc.... Install it and forget it. Its not worth the worry.

2. When you got the heated seats did you get the control buttons with it? They mount on the side of the console.
If not I would suggest trying to find an 88-91 car with the heated seats, get the control units, and follow the wires back into the wiring harness OR if you are good at reading wiring diagrams figure out where to connect into for power and what the fuse amp rating needs to be.
Ideally you could use the console from the 88-91 as a template for the location and size/shape of the hole for the temp and seat control button bezel.
2.a. Do the same for the power seat back adjustment wiring. Include the two pronged connector.

 

I've seen the result of a worn yellow fan finally giving up and letting go and it punched a hole through the bonnet and left an enormous mess and damage in the engine bay.

I wouldn't go anywhere near a second-hand fan for an XJS, Absolute false economy.

Cheers

Paul

 

Beartooth,

One thing I forgot. You can get rid of the dual coil's. A single aftermarket coil is more than sufficient. When these cars were new the electronics to fire a V12 at high speed wasn't quite there so to ensure ample energy they used two. The single aftermarket coils available since the 90's provide plenty of power and they allow a bit of a cleanup of wires running all over the place. About $40 IIRC.

 

Well, I actually already picked up a dual electric fan to retrofit... I pulled it out of a Ford minivan; it's the right height, but I'll have to trim the sides down a bit. I guarantee it pulls a lot more air for the money than a brand new aftermarket fan, and the motors themselves are available if one goes out. Probably easier would have been a big single fan: one that's really popular was out the the 90s 3.8 Tauruses, but I could only find 3.0s (probably be too small). I'm thinking I'll just hook one side up in place of the original electric fan, then figure something out for the other side. I'll probably go back to grab some wiring, and I might just go all the way to the relays and do my best to replicate the control scheme of the vehicle it came off of (I think it's old enough that it's controlled by temp switches and not the ECU). I might be making work for myself, but coupled with an alternator upgrade (I found Grant's great tip on the 115A Bosch alternator, which should be enough), I'm thinking it'll be a step up all around.

Cool, thanks! I was just reading a bit about that; looks like I've got the original coil setup (Lucas main coil, and another coil in front of the radiator). I was also interested to read that the ignition control module is just an HEI module with some filtering circuitry; now I'm tempted to hot rod the ignition a little with a performance HEI module and hotter coil. I'm not sure how much there is to be gained with that, but I'd hope at a minimum that a lower-resistance single coil would help. Aftermarket coils do start around $40 (even a bit cheaper); the brand name ones run about $75 and up. I seem to remember reading that E-core coils area a little more efficient, so I'd probably lean that way. I know a little more spark means you can run a little more spark gap; not sure how far you'd even want to go there... And with 12 spark plugs (some pretty hard to get to), experimenting is a lot of work. Speaking of spark plugs and gaps, I pulled four yesterday to see what they looked like. I'd say my problem is too lean, if anything. The gap seemed to be off - around .035. They were NGK TR5GPs; I'm not sure what gap those typically come with, so I don't know if mine were gapped incorrectly, or were just put in out of the box with too much gap. Anyway, it's snowing now, so it'll be a few days before I can get back to tinkering, but hopefully before long!

 

OK, my findingd pn s[arkers in this engine.

Fancy, dancy *****, NO, it does not work well, despite the marketing hype.

I run NGK BPR6EF in all of them, gapped at 0.025". I had stock pf BP6EF, NO resistor a while back, as my NGK dude told me they were stopping the Non R spec.

The "P" is Projected Nose, which means the gap where the spark happens is outside the cone of the plug, and right in the path of the Bang Juice. Meaning easier starting, smoother idle etc etc.

Coils, oh boy, glad I got freebies to try. I settled on a Fuelmiser CC215 Universal Electronic Ignition Coil waaaaay back. Its sits at 0.075ohms, so well under the 1.0 the Amp Module is limited to, and seems happy after too many years. As mentioned, coils of the era were not up to snuff, but todays are, and you dont need some rip snorter, arc welder style coil for this engine.

I also run an an Echlin (Made in USE), whoopee, module, TP45B, the B being for clister pack, fair dinkum, these narketing claowns are a soecial breed. Tried other brands, NOPE, and GM ones down here, good luck.

 

Found the missing PDF, so one more for your stash.

Brad, this for you also if you read this. Just tick the like tab. If no tick from you in a few days, I will go do battle with Outlook and send it, oh boy.

 

I got it. Thx. Hopefully pulling the distributor is not in my future.

 

I'm back, finally! I had a work trip last month, been trying to get some insulation work in the shop done and finally move some clutter up in the attic space. Anyway, yesterday and today I went to work adjusting the throttles. I figured maybe they're hung open and causing it to run lean. While I was at that, I replaced the missing pivot bushings with some plastic sleeves and cleaned the TBs. Then I checked out the TPS, which has seen better days. It seemed finicky near idle - hard to get it to hold a steady .32V. I took it apart, and sure enough, there are two tracks pretty well cut through the conductive material for around a quarter of the travel. I tried the suggestion of clipping and soldering to reposition the contacts, but I'm not sure if I moved them far enough. Maybe it's better, but it still seems inconsistent. I'm thinking now of moving on to a completely different TPS, using the Ford unit people talk about. I might pull a whole throttle body off something, then take it apart and throw away everything but the shaft and TPS itself, and graft the shaft into the capstan where the TPS mounts. Since those deliver too high a voltage at idle, I'll probably also run a resistor in line like others have. Going back to the throttles, I used a .002 feeler gauge as per XJ-S help, then adjusted the two rods until they just started to open the throttle and backed them off a half turn. I also verified that the vacuum line to the ECU isn't broken by sticking a hose into the line where it T's off the crossover tube. But then it occurs to me that I should verify it's not blocked by disconnecting it at the ECU and trying that again... Oh, and I broke one of the throttle microswitches; any suggestions on where to get one of those?

Anyway, my reward for all this meddling was that it ran... exactly as before. So that's frustrating. I'm getting the impression that the TPS shouldn't cause such drastic issues, so while I plan to address it, I don't expect much. I think I'll grab a coil and get rid of both the ones it's got, just to eliminate that. Then I'm thinking I'll lift the injectors with the lines still attached (maybe run some longer fuel lines to give me room to work) and check for leaky ones, and spray patterns. Maybe the injectors are all gummed and gunked up. Hopefully turning over those stones will finally reveal something. So far it's mostly been flailing with no real improvement....

 

Do not put longer hoses from the fuel rail to the injectors on. You will interfere with the hood coming down.

 

Take a hard look at the distributor venting and the AAV plumbing.

If the AAV inlet (backside of LH air cleaner housing) is restricted it is possible to suck oil past the seal and into the distributor.

Cheers
DD

 

From experience experimenting with TPS setups I can say that a slightly elevated idle voltage won't cause any palpable running issues; the engine will behave perfectly well. I've run for years this way. However, a possible issue is that the ECU won't recognize that the engine is at idle. I'll have to have more coffee and do some mulling on that.


If the ECU isn't getting any vacuum [broken line] you'll be running massively rich; there's no mistaking it. Black smoke. Chuffing engine.


Google "Snap action micro switch" and you'll get a hundred hits. Very common item.


What IS the running issue? I'm trying to play catch up. I didn't see a description of what the symptoms are. Maybe I missed it.

Hang in there. Almost all of these cars have been neglected and have a stack-up of multiple issues.

Cheers
DD