Hey guys. First post here, and my first jag as well.

I've just received my first Jag, a '78 XJS. Got the old pre-HE 5.3 and all in it. I bought it very cheap (long story short, I work for a jag/rover wrecker, we bought it thinking it was an XJ40, found out it was listed wrong and was a repo'd XJS). It's been sitting for 6 months but it runs fairly well, despite cracking fuel rail hoses which I'm fixing at the moment. It's got an occasional miss on the left bank but I can figure that out.

Rust-wise, it's pretty damn good, with only surface rust other than the jacking points, all four of which have rusted out. I can weld in some old ones from a good wreck we have stored away, but I'd prefer new parts, so if someone has an idea as to where I could get new panels that'd be great.

I've got experience with mechanical work so the engine/trans isn't a concern for me, since it's in good condition, however long term I'd look into a manual conversion. Initially I've looked at the Nissan RB25DET big box, being a great gearbox that can handle huge power (I own an R33 Skyline which has been reliably pumping well over 500hp through the standard box). Has this been done before? I would expect it to be quite an expensive swap, but I can get my hands on one. Alternatively, which jaguar gearboxes are good options to swap in?

Obviously it's not going to perform like a fully built RB30/25DET Skyline, and I don't want it to. I want a cruiser, not a track weapon. I'll do all the basics and try push a few extra KW outta the engine but I'm not aiming for huge power. Fuel economy doesn't bother me either.

Finally, since I don't have any real experience with these particular engines or transmissions, is there anything important I need to know about them? I can rebuild it myself if necessary, but if there are any little tricks or tips about them, I'd really appreciate it if I knew.

Edit: I forgot that I intend to modify the intake manifolds very early on. I'll run stainless piping to a pair of pod filters which look to fit in alright as it is. The current intakes are old and beaten up so I need to replace them.

Thanks in advance for any advice, and I'm keen to get to know the people in the Jag scene and learn more about these awesome cars!

 

Look in the first sticky at the top of the forum, and download the free "XJS Book", by Kirby Palm. It will tell you everything you need to know about what can go wrong with an XJS in over 700 pages. Doesn't replace a set of workshop manuals, but it is filled with practical advice.

Jon

 

Welcome.

When time permits, please do an intro in the "New members area".

Misfires on the PreHE are usually sooted plugs, that is a common issue with that D-Jetronic system it runs.

Black goo inside the throttle bodies is another issue that needs wiping out annually. Mainly affects idle.

New bits, try XK Unlimited in San Loius Obispo, USA. They restore these things, and if anyone has/knows of new bits they will.

DO NOT overheat it. A lot more forgiving than the HE engine, but still not a good idea.

Fuel pressure settings are subjective, but well worth checking. Around the 29 -31psi.

Some here have fitted the Supra TT trans, no issues that I know of, just the $$ to do the swap.

I wrote this the other night for another member, might be helpful.

D Jetronic Jaguar info.doc

 

We need pics!! And Welcome!