Wheeler Dealers GRM Episode 10: 1985 Jaguar XJ-S / L98 5.7L SBC swap

Alright, let's dig in! First, a budget update. I realize I never admitted what I paid for the wounded cat, a whopping $1900 quid. Yes, this is actually the most expensive one I've done yet! When I went into the workshop to get started on the old cat, I was greeted with a flat battery.

The battery was a new, higher-end Exide. I failed to notice the kill switch, which apparently needs to be thrown every night. Luckily, she charged right up no problem. Now it was time for a diagnosis. The Jaaaaaag took a long time to crank before firing, smelled strongly of gas, had a bad misfire especially at idle, and was generally down on power.

Surely the caked-up filter and dryer vent hose were doing no favors.

Closer inspection reveals a rebuilt Bosch MAF. Inspection of all of the casting numbers on the block revealed it to be a 1989 L98 5.7L from a Crammit. Further, all of the components on the car with part numbers also matched that same year/make/model, so at least we could assume that's what the lump was.

We obviously had some hack in here trying to diagnose the sick cat, as everything was labeled "1, 2, 3, 4" and "5, 6, 7, 8" on each bank. Small block Chevrolet's use "1, 3, 5, 7" and "2, 4, 6, 8". Hmmm... The injectors at least looked fresh, and a dig through the books confirmed that 2 were new and the other 6 were rebuilt and flow tested.

Pulling the plugs for a reading got met with disgust. They were sopping wet with fuel, pretty dirty for being so new (again, receipts in the books), and totally incorrect. Who puts Autolite's in a GM?!? They were also gapped at .050"!

Further inspection showed a badly worn cap and rotor, some chaffing on the plug leads, and this low-quality replacement ignition control module. Anybody that's ever owned this era GM can tell you that this module absolutely needs to be a top-shelf quality one, or you will have misfire issues.

We had an idea of the issues, a plan on how to correct them, and a shopping list. To the Batvan!

A successful trip to the FLAPS (okay, okay, unashamed plug, my employer!) rounded up everything needed to get the old cat back into shape, so let's dig in!

All of the parts dropped in without issue (remember to slather dielectric grease on that module!) however things were still not right. Some sleuthing showed the distributor to be all the way up against one stop. So I assumed everything done before me was wrong even though it ran and went from square 1 like it was a new motor. I labeled all the cylinders correctly, pulled the #1 spark plug, turned the motor over by hand until compression on #1, and pulled the cap to mark the rotor orientation. I put the distributor back to half way between the adjustment range, put the #1 wire on the terminal where the rotor was pointing, and followed the rest of the leads.

Low and behold, we had a running motor! A very well running one at that, that turned right on and didn't misfire! After she came up to temp and idled down, I located the EST wire (brown with a black tracer) and unplugged it, thus locking out the ECM's advance function. I grabbed the timing light and set base timing to the factory-spec 6 degrees BTDC, then shut of the motor. Following factory procedure, I plugged the EST wire back in and resterted the cat. She was spot-on now, and running great!

Next was tackling that ungodly dryer vent intake setup. I fashioned up a short run to the MAF with a fresh filter. It's no cold-air intake, but at least it won't hydrolock the motor and it's actually clean and leak-free. I also topped off all the fluids, did some wiring loom tucking, and installed nice plug lead separators to keep the wires off of the manifolds.

A test drive showed that we were done mechanically, the Jaaaag had a roar and she was actually pretty quick and nimble! Nice surprise, she also has a fully-functioning LSD and can lay elevenses for about 150 feet from a stop.

Now that the Jaaaaaag was running correctly, it was time to tackle the looks. The paint needed some serious help, so I did a test panel:

Oh yeah, that'll buff out! She's going to look mean all done up. Now a word from our sponsors while we go and do some more work.

Cool car. Steal of a price after that easy fix! Keep it for a year and Challenge it before selling!

So, all the guesses were right!

So awesome.

That car is crazy nice for under two grand. Personally, I'm a big fan of the L98 motors, having had one in my C4 vette.

It's not like XJS's are so rare or valuable that it is an affront to decency to modify one. At least this one is running and driving unlike most of them.

Jav, I have to hand it too you, you find some amazing bargains out there. I don't put it just down to luck, I put it down to your skill in picking the cars that appear to be fubbard but knowing things aren't that bad. Despite the fact I made a dig about putting a proper engine back in, this is cool and I kinda wish I had the spare change around to be your next happy punter.

This is going to be epic when finished.

I love these threads. Great work on the diagnosis.

That is awesome! love when it is simple like that. Congratulations!

Javelin wrote: remember to slather dielectric grease on that module!

Just a little note for folks reading this who might not know better, but you do not use dielectric grease under ignition modules. You use heat sink paste. That's what's inside of the little included packet. I'd hate for someone to go down the wrong road. If you're a nut like me, you can buy heat sink paste in bulk for short money if needed. I personally remove my modules and renew the paste whenever I have occasion to remove the distributor cap for whatever reason.

I did realize that the flex pipe was a major turn-off, so I brought the cat in to my local muffler man for a diagnosis.

Why yes, the world's cheapest mufflers were blown out!

Why yes, the flex pipe did run in between the suspension, hitting everything!

What a ghastly setup. Surprisingly, the original V12 exhaust was used from the manifolds to the mufflers, and was relatively nice.

So this was my solution. A new set of Thrush Turbo mufflers and some dowturns, welded on. No more exhaust leaks, and she was sounding much more appropriate now.

Next was the paint. It had hard water stains all over it, contaminants like crazy, and was dull,

Up close.

Bonnet.

Boot.

We can go over detailing preferences for days and get nowhere, but I'm pretty simple. A Porter Cable 7424 polisher with a 8" Lake Country head, using foam pads. I stick with Meguire's for my chemicals. On this car I used Polishing Compound and a hard pad.

Repeat on all painted surfaces until finished.

Bonnet.

Boot.

Beauty shots.

I also trashed the lame, smelly, gross seat covers and wiped down the interior with 303 Aerospace Protectant. Now she was ready to sell! I have listed the big cat on the list of craigs for $3500 quid or best offer. I will happily accept $3200 from a GRMer. Cheers!

Appears to be a steal at that price too!

Lof8 wrote: Appears to be a steal at that price too!

It's in the classified forums!

I have to do a road trip for work today, so of course I took the reliable British car with the hillbilly engine swap.

Excellent work on the car! Have you by any chance had an opportunity to look at the ecm or the wiring? I have a c4/l98 that is causing me grief. first the vats, then random no start, now the fuel injectors aren't firing. It's all crappy anti theft related so I'm curious if the swapper changed ecms or has a mastery of electrons.

lot of good XJS/XJ, V8 conversions going on, two that i'v been following ,one in Miami area, and other in Wisconsin!

Miami conversion using a 2012 Camaro supercharged engine, along with 6L80E trans, that one should be a kickass car,1994 XJS.

other one Wisconsin, a new crate engine ,FORD V6 Ecoboost twin turbo, much lighter weight.like 300lbs off the front!

both of them will be interesting

a pic of my 1978 XJS roadster,(maybe if i can post here?)

nope aint gonna happen, im old and dont know what URL is?

why is this site so diffecult to insert images? why cant it be like normal internet sites?

ronbros9 wrote: a pic of my 1978 XJS roadster,(maybe if i can post here?) nope aint gonna happen, im old and dont know what URL is? why is this site so diffecult to insert images? why cant it be like normal internet sites?

It's a right of passage. The site software is the embodiment of Grass roots. Build something yourself for pocket change and thousands of man hours when there is already something available off the shelf, and in this case far better too.

Find the image you want on line. If it's your own photo you'll have to upload it to an image hosting site such as Google Images, imgur, photobucket etc. Then once uploaded select the image you want. Put the mouse over the image and right click, chose 'copy image address' (which is the url) Then in GRM select the picture of the camera just above the text entry box and paste the address (url) into the box that pops up.

If you don't have an image hosting site I'm sure you could email one of us the image and we'd host it and post it for you.

After a few weeks relisted on CL I got tired of people coming to kick tires. They fell into one of two camps. Type A: "Why dunno you put a carb-u-tater on it ferrin some moar power?" and Type B: "Will you take $10 a week payments for it?". Obviously the local market was doing me no favors. I had successfully sold on eBay before (the Cadillac) but the fees seem high and the car not a good fit. I decided to try a GRM sponsor, Bring A Trailer. For those of you not familiar yet, BaT will cause you to become an alcoholic by emailing you a list of crazy awesome cars at low low prices every berking day. Maybe they could sell the cat for me, so I contracted with them at a $3000 reserve.

First I had to make sure she was as perfect as could be and take a bunch of photos, which I did. It had 2 headlights out, so I put in some new ones. I also kept getting a stumble at idle and no amount of sleuthing could find it. No abnormal vacuum readings, fuel pressure was great, plugs were reading good, coil output was great, it just didn't make sense. Then I remembered, BATCH FIRE! I pulled out the noid light and started pulling injector harness connectors off until the light went from dim to bright. Boo yah, the #3 injector had a bad winding. When that happens on batch fire, it will cause the output on the whole bank to be reduced. The car will actually run better with the #3 injector unplugged. I sourced a rebuilt injector but didn't want to install it because the auction had started.

http://bringatrailer.com/listing/1985-jaguar-xjs/

A week later after some decent bidding, it sold for $2500. Wait a minute, didn't you say it had a $3000 reserve?!? Well I did. In the BaT auction fine print, they reserve the right to pay you up to $500 to meet reserve in lieu of a relist or lost sale. SO the buyer got a steal of a deal at $2500, and I still made my profit at $3000. Win win!

Unfortunately then, this happened. I went to start the car to get it prepared for transport and the starter quit working. When I went to unbolt it, it fell out in 3 pieces. The bendix had jammed open while the engine was running and the engine won. Luckily the PO had had it replaced before with a lifetime warranty unit, so I was able to trade it out for $0. With the new one installed and the battery topped off, the old girl was ready to go.

Last night away she went, bound for Jacksonville, Florida of all places. The buyer is finishing fixing it up with his 14 year old son for his son's first car, which is way cool. They get to do the injector as the first job as I sent it off with the big cat.

So, how'd we do? Not as good as our recent streak to be honest. I overpaid at $1900 for the car. The tune up parts ran $150, headlights were $12, starter was $0, mufflers were $35 plus $50 to install, and the auction fee was $250 bringing the grand total to $2397 before incidentals like gas, insurance, and all of my shop supplies like the detailing chemicals. With the $500 back from BaT, I end up at pocketing $600 for my labor on this one, which was about 20 hours. All in all, a fun project that I hope the new owner enjoys as much as I did.

That wraps up this episode of Wheeler Dealers GRM, stay tuned for the next plucky motor.