Looking to buy '96 XJR6 project car
 

Dear all,

I'm looking at purchasing a '96 XJR6 w/ 160k miles. It is a <$1k project car, since it starts and runs, but won't safely drive. The seller has described the problem as:
"The throttle body sticks when you rev it up and come back to idle, it doesn't close all the way. It setlles around 1500 to 2000RPM. Attempts to clean while the TB is attached to the car didn't do much and has fouled the plugs - car now has a misfire."

I haven't seen the vehicle in-person yet, but I want to prepare myself with what to expect. I'm thinking:

1. If the car starts and drops to idle normally, and has a high idle after revving it, then the throttle body could be sticky
2. If the car starts and always has a high idle, it could to be a vacuum leak
3. There could still be a TPS or ICV problem
4. The misfire could certainly be tied to the owner dumping TB cleaner into the intake and fouling the plugs, or it has a bad valve cover leak in the spark plug wells

Do you guys think the same? This problem looks somewhat common based on my search, and the fix seems reasonable. I'll bring an OBD2 reader to check for TPS values, and to scan for codes.

The interior is supposed to be rough. I have no worries about the 4L80E transmission, that thing is bulletproof. I'm working on getting more pictures, but the cost of entry for this project isn't high. Would you guys do it, or would this quickly become a $5-6k project once I start chasing this high idle issue?

Manually twist the throttle return back to close and see if you get results . Stronger return spring with TSB See page 12 below :

http://www.jagrepair.com/images/TSB/...all%20R493.pdf

There is a good PDF by someone that accomplished this without a shop visit

EDIT: Pretty much what Lady P recommends. Beat me to it! then again I had to type an essay lol

This could be an easy fix from the sound of it. I had the same issue too (but I had the N/A engine), you hit the pedal (while operating at normal RPMs, 700 for example), the RPMs go up and stay at high idle. Well easy solution, most likely the throttle plate spring is no longer able to close the throttle all the way (hence the high idle). The way I fixed this was to hook a spring to the throttle body to apply enough force to close the TB.

You can buy the replacement spring but this will include removing the throttle body, TPS, which youll end up paying maybe a couple hundred dollars to have it calibrated. Which was my mistake.

Another thing it could be is to have the TPS re-calibrated. If the seller removed or messed with the throttle body in an attempt to clean it could affect TPS %.

https://cimg2.ibsrv.net/gimg/www.jag...a71437d5fe.jpg

To aid in your engine regulation see page 51 for the AJ16 engine . Engine codes page 121 for 1996 model .

To get more out of the SC engine you might later consder the " Andy Bracket " biasing the crankshaft sensor mounting and the different sized supercharger pulley . Both cheap and easy to do .

http://www.jagrepair.com/images/Trai...20-%202000.pdf

Wow, awesome, this forum is super helpful! I have some confidence in this then, will probably set up a day to check this out. Been wanting to do one of those beater rallies, and what better to do it in than a British Q-ship. I'm not right in the head.

See the above edited post . This is a 1995 normally aspirated inline 6 version with a exhaust system as a SC engine puts out about 30 % more from the factory .

No need to remove the throttle body, although it would be a very good idea to clean it up as its probably the reason it doesn't close properly.

A new spring is Jaguar part NBB3131AB, its visually slightly thicker compared to original spring and its definitely stronger. All that it takes to fit this is to remove the throttle cable and undo three screws from the top, lift the top of the TB where the cable routes, remove old spring, fit the new one in, put the top and three screws back on, fit the cable, job done. Literally a 15 minutes job and the spring cost ~$2 from Jaguar in UK.

As for your project, the idle/misfire issue should probably be the least of your worries.

Look for rust as this is always a major issue with these cars, the front floors where they meet the sills and the toeboard is usually worst. If this is gone its going to be very expensive unless you do it all yourself.

Few pics what to look for attached.

This is of course only if you're planning to keep the car for a bit longer then 6 or 12 months. If this is only a fun car for a short time then as far as its in one piece, dont go anywhere close to it with a wire brush or screwdriver, have fun driving it and sell it on later :)

Yikes, and the buyer's guide int he sticky mentioned to not worry about rust! This is a Northeast car, so it may have rust. I just hope it doesn't look as bad as a car from the UK!

From the buyers guide :)

"Body
These cars are built like tanks but even tanks rust. As with any used car careful inspection is required, and doubly so if the car has been used on salted roads. The rear wheel arches seem to be particularly trouble prone on X300s. "


I went thru all the usual high idle problems and fixes with my XJR/6. A couple times it was simply the throttle and traction control cables needing adjustment

Cheers
DD

Guess I didn't read carefully enough and checked out after "built like tanks" :icon_razz:

If it is your throttle-return spring acting hissy:
https://www.jaguarforums.com/forum/x...carman-111454/

Well, I finally received pictures of the interior and rust spot. I want to go check it out, but that windshield cowl rust really doesn't look good. I can't weld, yet, so that may be the deal breaker. He apparently has extra seats, but the plugs are different. What do you guys think, worth $800 or less?
https://cimg7.ibsrv.net/gimg/www.jag...5062296153.jpg
https://cimg8.ibsrv.net/gimg/www.jag...a324043c35.jpg

https://cimg6.ibsrv.net/gimg/www.jag...bcff08749.jpeg
https://cimg0.ibsrv.net/gimg/www.jag...8d2156e04.jpeg
https://cimg7.ibsrv.net/gimg/www.jag...e24b989a9.jpeg
https://cimg8.ibsrv.net/gimg/www.jag...10a6544dc.jpeg

There are ready made seat skins to replace the torn skin , not a cover . Not bad on price .

May not need to replace sheet metal in trough . They are plastic screws so be careful of the brittle cold .

The speakers rot and sound terrible and can be repaired yourself with about $ 40 in parts and you can Mod yourself a hardwire input jack into the original Jaguar stereo head to receive any device like CD , smartphone , or MP3 .

I have a repair of the center console cup holder without buying the Jaguar repair kit but you would have to find the leather on Ebay or junkyard

That trough area is where water gets in and corrodes the ECU connectors on the X300 so inspect the ECU unit by removing it to look down in , not a deal breaker and can be repaired by yourself . Below is a pic of the connector and wire color map I made months ago I gave someone else today :

The preferred plug for the AJ16 Jaguar are different in the S/C engine as they are Champion RY9CC and not the 12's I believe , I could be wrong . None of those exotic plugs .

Has it been started in a while ? If not may need some marvel mystery oil in the cylinders a few days before to loosed the rings radially for enough compression for a light off , it will smoke .

If the extra seats has the picnic table at least grab them and the taller shell back as they bolt on with the provided nuts on all of the seats without .

Headlight lenses can be swapped out with the latter X308 version for a cleaner appearance with the window chrome and leaper hood Jaguar that not all XJR's come with .

What's that tape on the headlights all about?

The owner of the thoroughbred stud farm I worked on as a teenager had a Chevy pickup with seats that looked almost exactly like that! He left the door open all the time and it doubled as his doghouse. Coupla big black labs....

The story goes:

"the back story is I bought in 2015 for $1400 with the intention of using it for a club racer. It was to be gutted, fitted with a roll cage, race seats, five point harness and etc. Also the bare minimum to keep it street legal. This was to be a joint venture with my son and I. We poked at the throttle body as much as we could being still attached to the car and began surveying the electrical systems to sort out what would be removed. Nothing invasive was done and the car is still as intact as the day I bought it.

Long story short, my son married a military girl, she got orders and they left. If I had the time to continue the conversion by myself it wouldn’t be on CL and that’s about it."

Well, I have plans to beater rally this. If money is there, it'll be a LeMons car too, but definitely not this year. The fate of this car will be the same no matter what :icon_angel:

Did a quick search. Everybody says the ECU is inside the vehicle. Is there an external connector I should be looking for? I plan on removing the plastic cowl and poking around to see if it's rusted through.

Edited above post

Most of the ECU wires with some exceptions go through the firewall with no firewall connector . Red arrow in pic

The ECU is by the right passengers right foot behind a small wall panel

There is 2 connectors together that has a history of corrosion issues , easy repair yourself and can put in temporary butt splices .

Pics coming

Awesome information. A lot of stuff to take in so I'll have to sit down tonight and absorb it all in. This forum has been great so far. Still waiting for the seller to get back to me with an address and time tomorrow.

So I went to check it out this morning. Seller firm on $800, and it just needed too much work for me given that I already have another project car.

Undercarriage was clean. One corner on the passenger front had rust showing, but you couldn't poke through. The wiper cowl area was indeed bad. Not punctured, but I could have poked through it with a screwdriver. It would have looked like this: https://www.jaguarforums.com/forum/x...-photos-87131/
Given that I can't weld (yet), this area would be an issue.

Rest of the vehicle needed little things. Motor mounts were also shot, he didn't have the key fob so sometimes the immobilizer would kick in, and of course the throttle body issue. The interior needed lots of little trim pieces too, and he did some wiring already to make the seats work, which scared me away since I don't want to chase after his work.

If anybody has the ability and familiarity with these cars, let me know and I can give you his information. Car is located in Williamstown, NJ.

Appears to have the wrong rear seats in it as well.... among other weirdness.

To me this looks more like a borderline parts donor car. It could be brought back, but the cosmetics are very expensive and that all appears to be in very poor shape.

Cleaning the TB on the XJR6 is a pain. On a good car, you can keep in good spirits, with a car in this condition, you might lose your patience ;)


.