Hello All.

First of all i want to tell a little story about my experience with this car and then want to ask some help from experienced XJ owners technician.
In the beginning i'll tell a little about my self. i'm from Republic of Georgia and i'm a car enthusiast. i'v owned lots of cars in my life to be exact 58 some of them was Suv,s Some Sport Coupes, Some Sedans. all kind of brands and styles also i'v built few turbo projects by my self and modified lots of cars. i was working as a Automotive Service manager for few years and got lots of experience from all of this i just wanted to mention that's iv seen lots of weird problems and solutions for cars and solved all of them

now about my XJR
i'v bought this car about 3 years ago. it came from Japan original LHD with Arden front lip and side skirts. i'v fall in love how it was looking from first look and still feeling same every time i see this car. it came with 149K km on it, body and interior was looking very fresh. it was kind of stalling on idle but i'v decided to take it anyway (was thinking its will be easy fix. maybe spark plugs or coil ) so story begins from that day.
i'v took car to the Service where i was working on that time and on second day replaced Spark Plugs thinking it will solve problem but problem stayed, after that started everything. in few days car started stalling more and even shutting down while stopped in drive. so i'v started searching problems and replaced lots of parts on it i'll list it here what i'v replaced and what condition i have right now. so replaced: spark plugs(few times, few brands. all with original specs) . ignition coils (firstly with used ones secondly with new ones) thermostat, water pump, main water hose. fuel pump (first installed same kind 2 fuel pumps, second time installed performance fuel pumps, third time installed single 205 LPH fuel pump, thinking to replace again and install 1 Walbro 255 LPH fuel pump) removed SC cleaned and installed few times. checked on air leaks.
all of this was happening for 3 years. and for this 3 years i drove on this car only 1K km from Service to Service.
most problem for me is that's i cant diagnose it properly because i don't know which diagnostic tool i can use on it for full diagnostics. i want to see live data. i'v tried few diagnostic tools but none of them shows live data at all. on the very beginning i'v diagnosed it with LAUNCH X431 and it was showing water temperature sensor. so i'v replaced both WTS s on top of the engine but error stayed. after that i'v replaced radiator WTS but same with this error, after this i'v installed it's own sensors but nothing changed in diagnostics. few month ago when i'v tried to diagnose it again error was gone but i don't know how. the exhaust was to black from inside so i'v noticed that car was working on rich and it could be a problem. i'v started searching why it could go reach and appears that's only 3 sensors can make it rich. 1 AFR, 2 Oxygen Sensors, 3 Water temp sensor. if i could read live data i'd easly determine what is the problem but i can't. also once i was high revving for few mins while moving and when open the hood i'v noticed that's exhaust manifold was ALL red. decided to check catalyc converters and they was almost melted so i'v removed them to let exhaust freely go out (was thinking it was the problem) also before i'v noticed that's car was running rich car was doing one weird thing. when it was hardly pushed and revving up it was hanging in about 4K rpm and bumping black smoke from exhaust (that's how iv noticed it was running rich) after removing cats this problem gone car revs up to the end without any holds. but it still stalls on idle. still shutting down engine, still burning out spark plugs.

now i'm going to order all 4 oxygen sensors and replace them as i think they could be the issue. but most important is how to diagnose it. if i can read live data i can easy fix it. an someone advice any diagnostic tool for this car?

also it has kind of problem with radiator fans. when both fans are connected they starting working when i'm opening igniton and staying all the time on. when i'm disconnecting lower one upper one starting working normally. turning on when hot and turning off when cooled down.

i'm trying to fix this badass

sorry for my English and if someone can't understand something i would be more then happy to explain.

 

Didn't see a model year listed, but your car apparently has the TSB mod for failing low pressure a/c switch or was built after that was incorporated into the build process. Your engine cooling fans should run in series (low speed) when ignition key is "on." Yes....all the time. If you need to do engine off/key on troubleshooting and don't fancy the noise nor battery drain, just pull the two 30A fuses in the small fuse box on the fenderwell in the LH Engine bay. Fans will switch to parallel (Hi speed) due to hi a/c head pressure or high radiator tank temp.

Doesn't sound like a known failure mode, but we've seen all sorts of strange behavior from failing crank position sensors. Could be the source of your stalling issue. I'd find, check, clean and secure the engine ground strap before changing that, though. Check the ECU connectors for corrosion. Many have reported water intrusion and subsequent problems.

 

thanks for your replay

car is XJR 1996. i'll try that with fuses when next time ill run the car.


im going to took out all engine wiring harness and check if everything is okay with it because i'v noticed few iginition coil wires had loosen isolation. also i'll check ECU on any rust or moisture. i'v already ordered new crankshaft position sensor and replace it in 2 weeks. (delivery to me from states needs 2 weeks)

 

With the 2 radiator fans there is 2 modes in which they run , this will cover the inline 6 engine only

Air conditioner freon pressure switches and coolant temp switches

With the mod done and the key on the left fan will always be on by the jumper wire mod on the low pressure freon switch .

As the freon pressure increases in high demand a second pressure switch ( 4 wire ) will turn both fans on , if you remove the cobbector and jumper wire Whie / Blue to either of the 2 black wires you will get both fans with the key on / engine not running .

The other wire Blue / Black to Black is the overpressure switch which disconnects the AC clutch temporary , no harm

In the coolant temp mode is you remove the 3 wire connector off the coolant temp switch ( not sensor ) on the lower aft left on the radiator you will find it has a black ground wire and 2 white wires .

If you take a paper clip and jumper one white wire to black you will get one fan , remove the clip and jumper the other white wire to black and you will get both . Key on / engine not running

This test run does not verify correct temp switch or pressure switch operation . But it does verify fan control module operation as well as fuses and fan motors .

These are low current switches so no arcing hazard

The fans are controlled by a fan control module which is 3 relays in one housing located under the car just Fwd of the left front wheel

Ask questions

 

Lady Penelope

thanks for this guide its will be help full when time comes to radiator fans. at this time more important for me is to run car in normal condition...

 

You really need to get diagnostic plugged in first here otherwise its going to be a goose chase and you'll be throwing parts at it. Try D900 obd scanner(plenty on eBay and cheap), this definitely works with an X300 and its a good solid interface for live data, I prefer it over Delphi OBD which also works and that would give you possibly more codes but its a bit of pain to use with computer needed to plug it in.

 

katar83

thanks that info was what i needed. i think i must have delphi somewhere in garage and tomorrow ill try to find it.

 

The engine cooling is more critical on the supercharged AJ16 engine and is more prone to head warpage

There is not a over temp light and the instrument gauge is not to be relied on

IMO I would square away your engine cooling first to protect it

Your IAV is a stepper motor and can be tested ( when warm as the region they fail )

The IAV is buried on the SC engine so you would have to read it at the ECU

 

 

If you put a meter on the center wire on the MAF meter and see 1.2 volts DC at the correct idle speed and see it go toward but not on the reference 5.0 volts DC on throttle up you will verify the MAF is alive . This does not verify the reading is accurate

Everything must be connected for this test so you can tap into the wire as it comes over the fuel rail wire bundle and the wire color is Green / Pink

See page 55 :

http://www.jagrepair.com/images/Auto.../jagxj1996.pdf

The MAF sensor part # for the SC engine is different then the normally aspirated and are mot interchangeable because of different ECU part # map data ( Hi XJR Engineer , chip Mod ? )

You are doing good in breaking down and defining your engine regulation issue

The higher level test is as Al Nz mentioned , this device ( referred to as ELM 327 ) goes beyond CEL codes and sees live sensor values as you drive around and record as a film

There is a general rule of thumb that for every 1.0 liter of displacement at 650 RPM you will have 1.o grams / second of MAF so in your case you should have 4.5 to 5.0 for the SC engine as a guess .

The ELM - 327 device Chinese counterfeit makers did not have an engineer on the team to get this right so it can be off by a factor of 10 or 100 is common so just multiply your reading to make sense ..

There is a Jaguar TSB on not running the engine above 2000 RPM in park

100

 

Lady Penelope
Today i'v bought ELM 327 and try to test the car. DTC s are clear as was expected. about live data i'v got some weird information. RPM, Coolant Temp., IAT, and few more sensors was read okay. the weird part was with AFM. it was reading 0.05 g on idle about 600 rpm. and it was reacting on accelerator. i'v disconnected MAF on running engine and it started very rough idle, loosing rpm and shut down in few secs. after i reconnected MAF and started engine rough idle stay and engine shut down. tryed few times and same result all the time. also MAF was showing 0.01 but was reacting on accel. most interested thing is thats all lambda sensors was showing 796.4C and was not changing in any condition. maybe ELM cant read accurate or all lambdas are dead (thats i was thinking before). didn't got to the ECU yet to check on moisture... car runs very rich. when i floor it in park it throws black smoke and some times i hear bumps in my exhaust.

 

The most important PIDs

MAF
critical
T{S , do not touch a this tine , critical tim e , , t ike stop , Will read 0.not touch to adjust at this tioe . will never read 0 $ a60 volts on it's middle wure at idle
O2 sensorresponce and lambda criticak value of 1.0

alternator voltage being steady throug throttle changes

ECT or closed loop mode in ECU

STJT ) noy a sensor but a final resukting outsome )G ckeaning of the thermistor bulb with the proper ckeanertarget value of 0,0

If the ECU sees a bad sensor it will default to a diferent set of data maps anfd not be optomum and thibd this takes time


E diting with bad vision so bear with me

 

Can someone gup in and straighten out my writingad

Eyes b

 

 

My eyes are better today so editing what I tried to write the other day

eUWS BAD AFAIM

Since you have more then one issue in different areas of engine regime we are propably not loohing ar a single bullet to load in the chamber , but ho lknows





Nad coil indusind drty electricity in y electricak system j


t onne he most important PIDs
f AF , clean thre thermistor resistor in the throat og yjr

criticalcr
T{S , do not touch a this tine , critical tim e , , t ike stop , Will read 0.not touch to adjust at this tioe . will never read 0 $ a60 volts on it's middle wure at idle
O2 sensorresponce and lambda criticak value of 1.0

alternator voltage being steady throug throttle changes

ECT or closed loop mode in ECU

STJT ) noy a sensor but a final resukting outsome )G ckeaning of the thermistor bulb with the proper ckeanertarget value of 0,0

If the ECU sees a bad sensor it will default to a diferent set of data maps anfd not be optomum and thibd this takes time