Very strange, Carl. If you just switch on the ignition but don’t try to start, does the dash (gauges, lights etc) look normal? If you leave the ignition on, then jump the starter (just to the solenoid, not directly to the motor of course), will it start and stay running?
And so sorry I missed your birthday–September 20? Happy belated birthday, Carl.
If you know what the drivetrain is out of it wouldn’t hurt to have a service manual with wiring diagrams to match it, along with the factory Jaguar info. It would give you a place to start at least, if this is a fuel injected motor you’re likely going to need it unless you luck up or find something obvious.
The drive train is an LT1 & 4l60 sourced from a 94 Cadillac fleetwood Brougham.
I do have the factory manual for the cadillac.
3, I do have the jaguar S 57 Schematic.
4, yes, next up is checking the “repaired” splice for p[ower.
Figure out how the Jaguar ignition switch powers not only the starter relay, but the GM PCM.
6, I can crank the engine by jumping 12 v to the starter solenoid.
thanks folks.
It might be a few days, I gotta get ready fr a visit to th eye doc and get a poke inthe eye… ugh
Pretty well the same as mine then, I don’t recall the GM harness really needing a heck of a lot to work to be honest. I bet you’ll find the gremlin pretty easily.
Also the coil-near-plug conversion is worth its weight in gold for the LT1.
That was essentially the only stumbling block these motors had as far as longevity and reliability, the optispark.
Thanks Bob. No prblem. I did not recognize your B’day either!!!
Rex.
Thanks I did not knw there was a coil on plug conversion for the LT1.
Mine does not have it. Optispark is there. Knpwing of the proclivity of failure in these units, I installed a genuine new GM unot at the time of conversion. Circa 20 years ago!!
Is it not the Ls series that enjps coil on plug?
Mine has the coil and amp up front on theleft cylindf head.
At te time of the last "no start’, I replaced the coil. It was not the issue. but, the coil that ran then remains in place.
This issue is a bit different. Teh prededing ne allowed a crank but no fre.
this one does not crank and of curse des not fire.
Agaain, I did jump 12 to the starter and was greeeted wit a healthy crank. Key was in the off , so no fire.
This setup I have uses LS coils in a similar configuration, yes.
I think we got ten years out of the new optispark when this motor went in, 100K miles or so. Not bad really, but when it started acting up it would kick back on start up and break the nose off the starter. After the 2nd broken starter it was decided the optispark needed to go away. It’s still there acting as a trigger for the coil control module but with no current through it they seem to be fine.
We used this one:
It’s been an install and forget it thing for years and a lot of miles now.
These guys have some really slick stuff, even a conversion to use an LS PCM
with the LT1.
Looks like for your current issue you’ll have to start with your ignition switch and see where power is and isn’t coming and going after insuring all the fuses and such are intact.
I agree Carl, I hate to see the decline in lumps activity. Johns Cars leaving, I’ve been here since 82 or 3. Lost a lot of my archived pics and discussions in the website switchover. Used to be a few pages every day of new posts. I still have the same lump from '82, the lump allowed me to keep my XJc back then as I didn’t have XK rebuild money. But even so, I still can’t bring myself to rebuild and put this euro L6 motor and triple su setup back in the car. The v8 horsepower is so nice and easy to maintain. Andrew has taken over the lead in the lump business and makes some very nice products and seems to lump more later gen Jags. He sponsors the other forum though so may not spend much time here. I do miss the activity here.
I have a password issue on the other one too Carl. Out of four computers three of them will log on no problem, the fourth one won’t. I changed the password once and I don’t want to go through that again. Suncoast, I was under the impression that Andrew sort of bought them out. I guess Mundorf just closed up, they were pretty good too.
Part of it likely just these cars getting older now, and while lumping is a balm for many ills, it’s not for all of them. And there just aren’t that many reasonably viable candidates anymore to generate new ones. You used to not be able to walk ten feet without tripping over an XJS or XJ6 with a good body and interior needing a motor that would cost more than the car was worth, less so these days. While it might be a little lonely online I get a heck of a lot of attention out in the world. My 90 is a decent looking driver but there’s no hiding almost a quarter million miles and I get stopped by someone just about every time I drive it. They have always been a relative rarity in most of the US.
It really has been. My father swapped the motor in 14 or so years ago and it was his work car if you can believe that. He got too old to want to get in and out of it awhile back and I bought it so it would stay in the family. As much as the purists poo-poo not having the v12, once you remove that from the equation and add the modernish overdrive trans, it’s really not needed much more than your average Mercedes or BMW of the era. That allows one to actually drive the car instead of having a 30 year old car with 50K miles on it that you hide from the world and only take out on nice summer days. Disuse ruins these things mechanically more than anything else.
They really are good drivers. Just don’t put your groceries near the outside edge of the trunk where the mufflers are unless it’s something that needs to be warmed.
Possibly the best part about these cars, is they age gracefully. Some cars, if the interior is a little worn or the paint isn’t pristine, they just look shabby. The XJS?
Every XJS is beautiful. It’s sort of like a truly beautiful woman ageing, every girl is pretty when they are young and pristine, but most of them can’t maintain that as the decades and use eats away at them, but the truly beautiful ones do.
The XJS does.
