Hello! I just figured I would start here. I acquired a 96 xj6 147k miles that is surprisingly solid and very straight for my area. I live in the Midwest on the Mississippi river. For any vehicle to survive winters this long is great. I paid only 500 for the car as a project. I have a son that will be driving this summer. Pretty sweet car for a 16 year old if i can get it sorted out. Anyone else drive these daily this old? It has ISSUES. MANY. So many, I need to prioritize and just focus on one at a time. The MAJOR issues are,

Right now Engine runs, but stumbles and even stalls on any accel. In Park.
Battery Light indicator is on. Vehicle has a reman alternator and new battery 2019. Will not charge. Seemed to be ok, a week ago Sunday. Voltmeter showed a strong 13V for an hour of driving, and engine ran great. Now i get nada. upper 10s lower 11 volts.
Transmission seemed to shift ok, a bit to early. But doesnt slip and hit all gears. Acted like it hesitated on the downshifts. Would not downshift at all on accel. rolling 30-50 mph and stomp on the gas would not downshift.
Power steering is junk. lost a quart of fluid in 10 minutes. I have not investigated yet but seems like steering rack seals are shot and one hose assembly is leaking.
Rear grinding sound? Wheel bearings? Brakes? I have no idea yet.
And front end springs seem weak. there is a rattle, but the coils seem bound up like compressed.

so, i need to get the engine to run and charge first. Im fairly mechanical. Not a pro. I have friends that are ASE certified. I have never wrenched on a jag before. I have a code scanner, but It is basic. At Present shows no issues, I cleared the codes and data. Not smart. Here is a listing of the info i had before i wiped it. Although the engine did fail and stall due to completely discharged battery upon delivery. I feel that some of these codes were set at that time. Now there are none, but i have not been able to drive the car to do drive cycles to let the computer do its thing.
P0302
P0305
P0306
P0727
P1313
P1314
P1775
P1794

I have been reading a ton on the forums and digging through the Jaguar .pdf stuff that has been posted here. With help from these forums i hope to get this girl back in her prime. only 23yrs old. good age.

 

Welcome to the forums Jeremy,

I've copied your Intro to X300 forum for advice from members with the same model.

Graham

 

Like a lot of mid 90s cars these are barely OBD2 compliant, so don't count on your code reader. a reported miss on cylinder 5 could actually be for cyl 1, etc

Reman alternators are big 50\50 depending on who did it, local part store brands tend to be the worst offenders. I'd recommend taking it to a competent rebuilder.

 

Yeah. Thats the next thing, i need to pull the alternator and see if its really running correctly. Its obvious the previous owner had amplifiers and subwoofers in the trunk. May have fried his new alternator as well.

drove it today for 10 min. Backfired out the intake a few times at park. Upon driving, the engine would cut in and out on accel or steady throttle. Lean running? I do not have a way to read live data.

 

Welcome, Jeremy and son. Be sure to include your son in this endeavor, he will thank you later. And you won't automatically become his mechanic!

Of course some investment will be involved to bring the car back to decent condition, both in time and money. But if you and your son can get involved, learn and do some work, it will be rewarding. Most of us with these cars drive them all the time and they are fine cars. Possibly the "easiest" older Jaguar to own. Obviously this forum is priceless for advice and assistance with all relevant things. The knowledge base is huge.

You will want to buy or download the parts and service manuals for the car. You can download from the links in the Sticky section above. You can also buy this info on a CD, A decent live data code reader is a useful tool, and of course a decent voltmeter. In the case of a charging and/or running problem, a battery charger is advisable, especially if you invest in a new battery. That way it can get a charge overnight while you use it during the day for cranking and testing the engine.

The battery condition is very important in this car. It uses a lot of juice. You may want to take the battery and the alternator to a parts shop to have them (hopefully) properly tested and diagnosed. NAPA has a hefty Group 93 battery for this car, in stock for about $140. The shops usually show Group 47 fits (which it does), but the 93 is a better choice for the same money. It has higher capacity and is a perfect fit for this car. I just installed one in my own car.

So, back to basics. Fuel, air, and spark make combustion. Fuel condition is important. a clean airway is important, and the spark plugs are very important.

You may have bad fuel, an old fuel filter, probably a dirty throttle bore, and possibly oil in the spark plug wells. All correctable at low cost. You probably need new spark plugs, as the old ones could be fouled from misfires (the 300 series codes above). Only use Champion 71. RC12YC plugs. Two bucks apeice.

One thing at a time, and you should be able to get her running right. These engines won't quit once you get them sorted out!

"Keep asking questions" as Lady Penelope used to say. Wish he were around here to help with this! He stopped posting and so far we don't know where he went.

 

1. Go to Amazon and order yourself a full set of QYL coils for the car. They are cheap and are the only coils, other than the OEM "Made in Japan" labelled coils, made by Diamond and sold by Coventry West and some other vendors.

2. Order yourself a set of new spark plugs. People swear by the Champions (RCC12YC or 71, which are the same) only, so I would recommend those, even though I have had good experiences with NGK. (BKR5e)

3. Order an OEM gasket for the camcover, aftermarket will NOT work.

4. Order a set of six spark plug gaskets, OEM, or the much cheaper URO, that will work as well. Do not use any other brand(s).

5. Order a set of 13 camcover screw gaskets from Rockauto, NBC2575CA, you won't find them cheaper.

Go to town and install these things. Basically, you start by:
1. Unscrew the coil cover plate. (3 torx)
2. Disconnect the six coils.
3. Discard the coils.
4. Unscrew the 13 bolts from the camcover, keeping the torx bolts and washers, but discarding the rubber gaskets.
5. Remove the camcover and peel off the gaskets from the spark plug wells and the camcover itself. You'll need a generous amount of carb cleaner, plastic scrapers and q-tips, to clean everything up.
6. I'd replace the spark plugs at this time. Check the gaps for 0.035" and torque them in at 22-28 Nm (17-20 lb ft). Don't forget the anti-seize. You can do this after you put the camcover back on as well, but you'll need an extension for your ratchet.
7. Install the new camcover gasket and six spark plug well gaskets and re-set the camcover.
8. Using the new 13 gaskets from Rockauto, screw the bolts back into place and follow the directions here: https://www.jaguarforums.com/forum/attachments/xjs-x27-32/5640d1287410224-t-s-b-s-12-60-camshaft-cover-oil-leaks-%96-aj16-engine-%96-bolt-torques.pdf
9. Install the new coils and plug them in.
10. Reinstall the coil cover and you should be good to go!

The codes should then be reset, then restart the car and come back and report what codes, if any, come up.

***along the way, you should be inspecting everything for cracks, breaks, things that could cause any car to misbehave, remember the parts you're working with are about a quarter century old!

 

rear brake pads possably worn out and scrapping rotors,or internal park brake shoes rubbing [ rusty surface].rear calipers bolts are secured with aviation wire,you can get new stainless wire and plyers at harbor freight,steve.

 

Hello sirs!

I fitted a set of QYL coils and champion 71 plugs over the weekend. corrected alot of the engine troubles. Thank you! I purchased an oem cam cover gasket, and plug well seals and all the bolt seals. I was VERY surprised to find no oil in plug wells, so ive left it alone so far. I need to remove the cover and have it painted/coated at some point. During this drive around, the battery light was still on, but it drove much better. But now has the high idle problem.

After cleaning positive post connections and ground points in many locations and tracing testing wires....i decided to remove the alternator. It was fitted by a previous owner last year. They must have damaged it. The main charging post was loose. Local supply house warrantied it! Surprising. I mounted it yesterday, and worked beautifully. Volts show 13-14 on dash meter under heavy load. Battery light gone. Idle issues gone. This car does look like it had a giant 93/95 series battery? and someone swapped it to a 47 group last year also.

Next up, power steering. It loses almost a quart of fluid in 10 minutes. ouch. i need to get under there and investigate. I know one pressure hose/pipe is shot. The leak pattern on the road suggests 3 separate leaks. maybe rack seals?

and....i have door locking issues. I believe its related to lock up/down switch or door open/closed switch. I am unable to lock the vehicle. This is a concern after i repaired the boot wiring at the right hinge, and now the open button works on the boot lid. it wont lock now, because i cant lock the car. LoL

Please feel free to move, bump or copy this thread or post to anyone that may have input on these issues. I have MANY. I am just trying to prioritize them.

 

Well done so far!
Is the locking issue with the fob or can you not lock with the key?
What happens if the car is running and you press the lock switch on the dash?
Does it not lock when you drive off (anti highjack)?

 

High idle doesn't surprise me. It's a common issue with these engines when there is work done to the coils/plugs.

You need to have your TPS (Throttle Potentiometer Sensor) reset. There's an easy way, and the other way.

The easy way is to have the dealer, or someone that has access to a diagnostic tool with the Jag-specific software. The dealer should charge an hour's worth of labor, even though it takes about 20 minutes.

The other way is to manually adjust the TPS in place. I'll try to find a link with those instructions shortly.

 

https://www.jaguarforums.com/forum/x...-150942/page2/

Post #26 will give you the procedure to TEST the car's ability to get to the proper idle. It's only temporary, but will show you where the car should be when idling.

The manual procedure to adjust the TPS regularly refers to getting your TPS to 0.6v, but if someone has previously done a TPS reset, that value may have changed, so you may have to rely on resetting the TPS so that the idle matches the conditions. A warmed up engine will idle at about 580rpm. A cold engine will idle at about 700rpm.

https://www.jaguarforums.com/forum/x...l-same-181845/

Post#4 shows you what's what. I would highly recommend taking that throttle body off, going through some rags and a can of carb cleaner and really cleaning that part out. It gets gummed up over time, especially when not in use. That part on the bottom of the second picture is the TPS. You'll want to loosen the two torx bolts that hold it in place so that you can, even so slightly, adjust, or rotate, that sensor, while it changes your idle.

If I were you, I'd remove that throttle body, clean the hell out of it, (which isn't costly, difficult, or even time consuming) and put it back on, adjusting it such that the TPS is set to 0.6v, then go from there. There's a great possibility that 0.6v is where it should be at, and if it isn't, then you're now in a position to make the adjustment, then lock it down. You'll kinda be doing this in the blind...and if the engine is hot, around a confined area, so be careful.

Here's another post that should help:
https://www.jaguarforums.com/forum/x...y-free-164263/

 

The high idle, settled down quite a bit after the new alternator was fit. who knows. I'll watch it closely. In park, 900. Drive, sitting on brake its about 750. While moving taking foot of gas, the rpms do not drop though. Stay about 1500+ I am certainly capable of cleaning the body and rough setting the TPS. what are the chances i screw it up and have to take to dealer for TPS reset? Closest would be 2 1/2 hours away for me.

Locking. So i do not have any fobs for this car. And to make matters worse, someone changed the handle and tumber on the drivers door so i do not have a working key for that either. The locks all cycle up and down. When you hit the lock button on dash they lock and unlock immediately. Manually pressing the front door locks...makes them all cycle once. Rear doors do not. ? I am not sure how to go about troubleshooting if each door is sending a signal for lock/unlock status. The door open light in instrument pack does light with each door opening closing, with car on. with no key the dome lights all light with each door, and do cycle off after a bit. Im assuming this problem is a door lock "out of sync".

This is just a fun project id like to turn into a daily driver. I only paid 500 for it. It has a very solid body shell. Just LOTS of neglected issues. So far the impressive group here has been very helpful.

 

after 30 min of driving today new coils did NOT resolve the random engine, cut in and out issues.

 

Undoubtedly, it's cured most of the codes? The p030x codes should all be gone.

Let's focus on the engine cutting in and out. I'll need more info on that. What is the car doing at idle? Is the gas pedal smooth when you apply gas? I'd love to know what your fuel trims are.

I would still suggest a cleaning of the throttle body, a sticky gas pedal is a sure sign, but it doesn't mean it's not due if it isn't.

We also need to cure the high idle. You could have a malfunctioning TPS, although I'm not ready to call that in just yet.

You might have to clean up the MAF? It may be dirty. They make a spray for it, sold at auto parts store.

Could it be oxygen sensors?

I think we need to focus in on this issue and provide a more thorough description.

Thanks.

 

I drove it for an hour today. Idle was better. Sometimes even all the way down to the 580/600. Gas pedal not sticky. Only had a hiccup once. Almost like the engine speed and transmission speed did not match? No codes thrown. I am working on a solution to read the fuel trims and throttle plate position live. I suspect possibly TPS issues as well, the vehicle runs better with each outing, but will NOT downshift on heavy accel at any speed. Maybe the computer is not receiving 90% or more throttle? Sport and Normal mode, switch does not illuminate, but I can definitely feel the sport setting engages and has higher shift points. On decel, every downshift is felt as well, almost like the convertor is not "letting go" of the input shaft of the transmission.

I have the locking issues resolved. The drivers door tumbler fell apart and is in 2 pieces inside the door. The key would never reach the bottom of the receiver and thus not hitting the last pins. So it seemed to me that the key did not fit the door. manually moving the lock/unlock cam on the inner door latch assembly made all the locks work properly. Previous owner has found a key fob, which would be helpful, and I will receive it next week.

Before i cleared the codes in January, by mistake, there was a freeze frame detected. I do remember one of the fuel trims was pegged at -100. Dont remember if it was short or long. Engine does act like its ok, but not quite as strong as it should be. I need to pull all injectors while im at it and see about having them tested and bench flow checked.

I found some hackery in the wiring loom in the Right fender. Previous owner confirmed, that the wires had fallen and rubbed on the wheel. I will be sourcing a replacement loom here as well. This could have shoddy connections and be the source of my random issues.

I will continue to update you all often, thank you for all your input! I have been through a number of vintage volkswagens, then mostly GM vehicles. After 15 years or so I am back to a project car and why i chose this European Jag who knows. But I like the girl and will slowly get her back to top shape.

 

Alright, I can stay with you with the engine. You keep telling me what the problem is and we'll get this thing done.

The -99 was likely the LTFT. The 95 had that issue with their programming, perhaps your 96 was still using some 95 programming. In any case, that info won't help. I was hoping to track down a vacuum leak.

If you still have a high idle, the transmission will not be coordinated, since the TPS isn't calibrated. The ECU is supposed to be able to "relearn" the position, so the more driving, the better.

While I do not think cleaning the injectors is a bad idea, lets make sure we take care of some low hanging fruit:
1. Spray clean the MAF
2. Clean out the throttle body. Be careful with the cleaning solvents because the TPS is at the bottom, and fluid will collect there if you spray clean it in place....although it's best to take it off.

After cleaning the throttle body, you may be back at the high idle again, but if you did this right and too the throttle body off, you should be able to figure out the "manual" TPS adjustment method. That should get your idle perfectly.

 

okay!

Ran the vehicle yesterday for an hour or so, idle was perfect sometimes, other times not half as bad as it was. 800-900 in D 1000-1200in park. It would not kickdown or downshift on accel at all. Today I have it apart. Cleaned MAF with special solvent, and throttle body. Throttle body was fairly dirty but seemed smooth. LOTS of oil the rubber boot and air intake. Is there no PCV valve or filter on these cars? I removed a ton of oil sludge, almost grease from the intake. I have the body as clean as i can get it, with small brushes and clean white cloths. Right now, backprobing the center terminal on the TPS, to ground. With ignition ON, I read .05V. Yes ive checked the ranges. it was 550-600mv. is there a chance this correct? or did you mean .05v when you said .5. it seemed to rise in ohms evenly also, no dead spots or odd readings when sweeping the throttle open VERY slowly.

Throttle cable seemed like it has alot of slack in it. I cant quite tell if the kickdown switch was keeping the throttle from 90-100% either. I have backed it off a bit right now. I do notice the switch is also an end stop for the throttle. the throttle plate can open past 100% if this is not adjusted correctly.

Im starting to reevaluate if we can keep this sexy girl. Yesterday investigating what i thought could be rear wheel bearing noise.....its the output shafts and Differential. Woof. Ive never tackled any tranny or diff work before, and honestly scared to. Now im afraid to drive the car as the in/out play on the LH rear wheel at 12 oclock was ALOT. maybe 500mm? its not in the U Joints, you could see the output shaft yoke moving in and out. I dont want to grenade the differential when right now its possible to be rebuilt, with no gear set. just bearings.

 

also, because i thought...what the heck i'll try it....this car runs nearly the same without the TPS even on the vehicle. Its sitting on my desk right now. Its safe to conclude that is one of my problems. I think i know someone with a benchtop power supply. If i can get a good 5v input we can check it on a scope also. idles at 1200 warm in park, 800 or so in gear. After the Throttle body, air intake, and MAF cleaning. Its very odd it doesnt throw a code in the ECM. but this is an early year for OBD2. I can only assume its running solely on the MAF sensor feed, as this is what the main fuel curve is calculated from? Super odd. I have a used ebay TPS coming, if that one is DOA sadly i will most likely break the car then. Power steering, Air Conditioning, Front Suspension, Rear Differential rebuild and new TPS will be too much to put in this old girl. I only have 590 dollars in it. what do you all think?

 

Without the TPS, the car will run in open loop, ignoring the sensors in the car. It cannot go into closed loop until it receives signals from a set of sensors, the TPS being one of them. So the car will run, but it should be overfuelling, so I wouldn't recommend running it that way for long.

Warm engine idle is about 580rpm.
Cold engine idle is about 700rpm.

The OBD2 system in the car is very stingy with codes. They're very useful when you get them, but unfortunately not getting a code doesn't cross anything off the list.

The TPS is certainly pricey. There's no guarantee that the one you bought will be good, so I can't really comment on that. The TPS should be at 0.5 volts, not 0.05 volts. (your millivolts reading converts to the correct decimal point) Fully open it should reach about 4.9 volts.

Throttle cable slack should be the cause of the 'no kickdown' issue.

There is an oil separator "egg" if you follow the hose that comes out of the top of the engine camcover. It does the job poorly. The egg is also prone to splitting, since the plastic egg is located up against the side of a hot engine. I installed an oil catch can, that (coincidentally) seems to keep the throttle body clean. I have that process posted somewhere on this forum. It catches a lot of condensation, so it isn't completely maintenance free either.

 

I am just hoping here the tps i receive on wednesday will be ok. I dont think this car has run in closed loop since ive owned it in january. If I must buy the right TPS sensor i will. I adept enough to attempt adapting a different one to the bottom of the throttle body. As long as its 5v, clockwise rotation, and 4000 ohm resistance. The faulty one off the body says made by CTS and FORD right on it. Maybe someone switched factory one with a Ford Scorpio TPS many years ago? Either way, it has failed.
When the used throttle body comes on wednesday, I will bench check the tps on it. Maybe even use a scope to check the resistance across the entire band.
This is a fairly early model 96. There is no egg on the breather tube. A facebook member led me to an add on kit that Jaguar released during some TSB? There are egg kits on ebay right now. I just need to stick with one thing at a time. The amount of oil sludge in there was concerning.

Thank you for your replies thus far.