Jaguar XJ6 X300 3.2

Post pics of your car in here
Will01
Posts: 590
Joined: November 26th, 2012, 3:50 pm
Location: Dumfries, Scotland
Contact:

Jaguar XJ6 X300 3.2

Post by Will01 »

Here's another little project that i am currently working on, this was a summer bargain buy.
Again like most of the cars we have it needs a bit of work, like most of these XJ's it will require a new rear wheel arch on one side and a good clean up on the other. The front section of sill will get a good clean up and a bit of welding but otherwise its in a solid condition.
The exhaust has already been replaced during the winter as the front pipe started to blow, we also took the opportunity to replace the Twin Cats aswell.
When we first purchased the car it was leaning over to one side, luckily this was an easy fix with new dampers and bushes. We took the opportunity to upgrade the front dampers to be a little more sporty, the rears may require at somepoint soon but at least the car now drives straight and true.
We came across a replacement XJR steering rack, so next time we are under the car this will also be fitted to help give a slightly better drive. This really is a very comfortable car to drive like most jags are.
Apart from work listed above the only future plans will be to keep the car running and upgrade parts as and when they fail as well as a good clean up with the paint.
We also have a plan to use this as a backup or cheaper option for Wedding Car Hire.
Attachments
IMAG0149.jpg
IMAG0149.jpg (54.33 KiB) Viewed 24214 times
GC_21
Guy Croft
Site Admin
Posts: 5039
Joined: June 18th, 2006, 9:31 am
Location: Bedford, UK
Contact:

Re: Jaguar XJ6 X300 3.2

Post by Guy Croft »

needs a GC prepped head - get 'em to the church on time...

G
Guy Croft, owner
badlyworntoy

Re: Jaguar XJ6 X300 3.2

Post by badlyworntoy »

These things are seriously underated. I had a 3.2 XJ8 sport about 3 years ago. knocking out 300bhp and thats not the fastest one either... try an XJR with nearer 400bhp, they have the best suspension and brakes on a road car I've ever experienced some serious supercar performance. You can pick them up for peanuts because people dont want to pay £250 a year road tax and have bigger fuel bills than the Exxon Valdez.

Getting rare folks, experience one before its too late.
Will01
Posts: 590
Joined: November 26th, 2012, 3:50 pm
Location: Dumfries, Scotland
Contact:

Re: Jaguar XJ6 X300 3.2

Post by Will01 »

Nice GC head sounds good, is that with the fancy looking pistons aswell?
I reckon we just leave this engine well alone, but a GC head on the E-Type would be very nice. I am sure we have a upcoming engine build at somepoint since the engine is starting to smoke a little, probably something to do with the fact its done 140,000 hard miles.
GC_21
Will01
Posts: 590
Joined: November 26th, 2012, 3:50 pm
Location: Dumfries, Scotland
Contact:

Re: Jaguar XJ6 X300 3.2

Post by Will01 »

So the car hasn't been used much as we have had an intermittent starting problem. I have done lots of searching online and have a few possibilities that I have worked through. Its interesting but the coolant sensor has been giving weird readings so this will be replaced. Also the oil pressure sometimes works and sometimes doesn't again I suspect the sensor. The fuel gauge on starting flutters on cranking also. Maybe these fluctuations are causing the ecu to get confused and preventing startup?
The other thing I have noticed is that if you spray a tiny little bit of injection cleaner up the intake pipe the car starts! Maybe I am wrong but could this be fuel feed problem e.g.fuel pressure is not high enough to allow start? If you try to start after it has run the engine starts no problem! Anyone got some ideas?
GC_21
TomLouwrier
Posts: 333
Joined: July 28th, 2010, 3:09 pm
Location: Leiden, The Netherlands
Contact:

Re: Jaguar XJ6 X300 3.2

Post by TomLouwrier »

hi Will,

Weird electrical problems that come and go, plus the fluttering instruments under starting suggests mass problems to me.
If the engine has lost it's proper mass connection to the chassis the current will find other ways, including your wiring and things like the throttle cable. I've even seen a throttle cable once that started to burn off the plastic cover because of that.
And yes: that can certainly upset your ECU, either because of the voltage dropping (ECU cuts out or can't drive the injectors properly) and/or because of the noise that may get on the signal lines (ECU gets confused).

Check all mass connections and see what the voltage on the instruments and on the ECU does when cranking. Check the battery under load.

regards
Tom
GC_29
fingers99
Posts: 99
Joined: December 9th, 2009, 6:24 pm
Contact:

Re: Jaguar XJ6 X300 3.2

Post by fingers99 »

Yes, earths I suspect. Scrape clean, silicone grease, re-attach.
GC_06
Will01
Posts: 590
Joined: November 26th, 2012, 3:50 pm
Location: Dumfries, Scotland
Contact:

Re: Jaguar XJ6 X300 3.2

Post by Will01 »

Thanks guys, i will check these also. Just really bugging me. I know that Jags tend to be great with electrical faults, lucky me.
I will update more when i know more and it starts working properly again.
GC_21
Rallyroller
Posts: 89
Joined: May 31st, 2011, 2:40 pm
Contact:

Re: Jaguar XJ6 X300 3.2

Post by Rallyroller »

Hi WillGood luck with the fault finding.

I had a 4.0L straight six version of one of these. A real joy. Sheer luxury, and gives you that one up -manship feeling when driving it.
I had no issues electrically over a 3 year period, but there was a starting issue due to "software" faults. If you started the car and then stopped it (for example reversing out of the garage, and then stopping the engine when you went to close the door, )the engine would not restart.( at all!)

After much investigation on the net, the solution was to remove all the plugs, poor oil into the bores, refit plugs and try again. Apparently the soft ware fault massively over-fuelled the engine, and this washed the oil from the bores so reducing compression. I am not quite sure what this says about Jaguar engine tolerances, but I don’t think they have a particular issue and the engines do last a long time. As you can imagine, this only ever happened once to me.

I did purchase a CD of the Jaguar technical manual. This was a great item. There were over 160 pages of electrical diagrams, but more importantly they had checking procedures for all of the modules, even down to resistance values on the multi pin connectors.

The suspension (on all Jags) seems to be the weak point. A lot of bushes etc that need replacement. I swopped the XJ for an S type (4.2 V8). What an underrated car. Fantastic. Still wish I had it.

Nigel.
GC_13
Will01
Posts: 590
Joined: November 26th, 2012, 3:50 pm
Location: Dumfries, Scotland
Contact:

Re: Jaguar XJ6 X300 3.2

Post by Will01 »

Thanks Nigel, i think it may be worth while investing in such a CD. Definitely sounds like it would be handy.
Lets hope we can get it going properly for not alot of money.
I agree with you on the suspension i have already replaced some of the front and fitted new dampers, what a difference it made. THe rear is a bit soft now so that will be next. Luckily the miles on this car are very low so bushes hopefully will be ok for another few years as it is a big job to replace some of them.
GC_21
Will01
Posts: 590
Joined: November 26th, 2012, 3:50 pm
Location: Dumfries, Scotland
Contact:

Re: Jaguar XJ6 X300 3.2

Post by Will01 »

So just a quick update, unfortunately the car is not going to pass its MOT as it needs to be able to start without help. Unfortunately i still cannot get the car to start on its own!
So far i have replaced Thermostat housing temp sensor for ECU and temp sensor for dash, i have also replaced air intake temp sensor, fitted new air filter, new plugs. The maf was also removed and given a good clean with injector cleaner, but i think we may invest in new one anyway.
The crank sensor is ok as it is reading and the dash tacho is working when being cranked. I did give this a good clean anyway as it is on front of engine and collects lots of crud.
I still need to change oil and filter and fuel filter, but i not worried about these items as i have fuel pressure and the oil is at correct level. When it starts running again properly i will change oil.
I still notice that the oil pressure sensor is very temperamental so i think this may be confusing ECU and not allowing the start? Maybe it shuts down the injector rail or prevents spark? Personally i think it stops injection as it will start if you spray a little easy start in intake. Once started we have noticed the car much better and the idle has lowered and running much better, i think this was down to the temperature sensor as the temp gauge was also very temperamental.
GC_21
Biancorally
Posts: 50
Joined: July 9th, 2011, 2:30 pm
Contact:

Re: Jaguar XJ6 X300 3.2

Post by Biancorally »

Hi Will,

Even, if oil pressure sensor is very temperamental, it has no effect on start. If my memory serves me right, on the fuel rail in the harness there are bonded cable connections. It may well be that the problem, start there!

Regards

Daniel
GC_17
Nobby
Posts: 87
Joined: August 24th, 2010, 11:58 am
Contact:

Re: Jaguar XJ6 X300 3.2

Post by Nobby »

If the coolant sensor is kapput then its more likely to be temperature/cold start related no? i.e. the ECU isn't accounting for enrichment due to cold engine etc..

Does it ever nearly start or cough upon startup?

If you think its fuel pressure or injectors related then you can always check signal to injectors during cranking or even pop a screwdriver on the injector housing and you should be able to feel it clicking. Fuel pressure wise then its only really going to be fuel pump (can you hear the hum?) or get a gauge on the fuel line.

I assume you aren't getting any error lights on the dash during cranking too. Dependant on year an OBD reader will help a little but I'm not sure how much functionality is supported a jag of that age.
Chris Burgess
GC 01
Will01
Posts: 590
Joined: November 26th, 2012, 3:50 pm
Location: Dumfries, Scotland
Contact:

Re: Jaguar XJ6 X300 3.2

Post by Will01 »

So I have now replaced the oil pressure switch and along with the other new sensors previously fitted the car actually started. However only once! Every now and again it starts but is still not reliable.
So I have also started looking at relays in front engine compartment. I unplugged all of them and tried swapping around. This now means the car starts more regularly however is still not reliable. I also had a look at the lambda plugs and swapped over and with all these changes the engine is running alot smoother.
Next job as previously mentioned by others is to clean up all connections, fingers crossed this holds the cure. Otherwise I am very close to rigging up a can of easy start to the induction hose permanently! Only joking, but this is very frustrating.
Wish me luck, I will update when I know more. Thanks again for the advice I will look at the wiring.
Nobby before changing the op sensor the car would cough once. If you had your foot fully depressed on throttle it may have started sometimes. But you would have to leave for hours to get another chance. Now I really do think it is down to poor connection. I will be taking off throttle body and giving a good clean anyway as I found this was a problem on my Alfa once.
GC_21
Will01
Posts: 590
Joined: November 26th, 2012, 3:50 pm
Location: Dumfries, Scotland
Contact:

Re: Jaguar XJ6 X300 3.2

Post by Will01 »

So we think we may have now sussed this no start issue. Hopefully!
I managed to get some help from my Dad and whilst he ways cranking the car over and switching the ignition on and off as requested i went through every relay and plug i could find under the bonnet and testing for voltage and checking connections etc. In the end we resorted to getting the car started up and pulling relays out until the car would cut out. Drastic i know but, we did eventually find a relay that would kill the car immediately when pulled out. This was then replaced and then found the car would start, however it sometimes wouldn't unless you wiggled it around and unplugged-replugged it back in. I tried swapping relays over and this also seemed to make a difference.
So we have ordered a spare brand new relay to try, also we will look at blitzing all the connections and cleaning them up.
Fingers crossed this has found the problem start issue and we can get the car cleaned up, fix a little welding and get her MOT'd ready for Summer.

We know have our first 'maybe' Wedding hire for one of the old Riley's and we would like the Jaguar X300 to be a backup and provide lifts for the rest of the wedding party. Therefore it is important we get her fixed up asap.
GC_21
Post Reply

Who is online

Users browsing this forum: No registered users and 8 guests