The AJ6 engine also originally came without catalytic converters which is the component unable to handle the lead. I think that catalytic converters were introduced for the 92MY? The diference is the ignition timing. The leaded bracket results in advanced ignition timing but I am unsure of the degree difference between the two.

 

That's great to know about the 92 model year change; I live and learn and am constantly amazed at how helpful and knowledgeable folk are out there. Thanks.
Finally sorted my '96 X300 Daimler 4 litre's poor fuel consumption by fitting new lambda sensors. An increase from 18.5 to 29 MPG is very welcome. Now trialling Andy's timing bracket to see how that goes.

 

I have a lambda sensor to change, as well. 15-16 mpg, isn't that exciting. One of these days, I'll get one of Andy's brackets.

 

KiwiTD, where are you in NZ? - I'm in Hawkes Bay

How much did your new Lambda sensors cost, and where did you source the parts? did you fit yourself, or get a mechanic to do it for you?

I am lucky - there is a local self-employed mechanic who is Jaguar-trained and has the diagnostics for my X300 - haven't needed him yet.

 

that is crazy! Did you change all four of them or ??

 

This is where I got my oxygen-sensors for my XJR a couple years ago quick and reasonably priced have used t them for a few different cars now post to Australia so NZ shouldn't be a problem OxygenSensors.com

 

Hi AL NZ.
I'm in Kapiti - Waikanae to be precise.
I get my parts from Jaguar Parts | Land Rover & Range Rover Parts | British Parts UK . Their prices are very good - the Lambda sensor were 56 pounds each, so with our Pacific Peso being reasonable at the moment not too expensive. Parts normally arrive five days after paying - postage is expensive though so the US source may work out cheaper.
I changed them myself; took about 45 minutes total. The top one is easy enough especially if you have a long socket with a cutout for the wire, and the bottom one is easiest (only possible) from under the car. 17mm heads from memory.
I also modified the wiring to make the plugs easier to access - the connecters are at the left rear of the head and a bear to get at. Somewhere on this site there's an explanation of what to do.
Be careful refitting as the sensors have a short soft thread and are easy to cross-thread. Suggest coating the threads with copper-slip or similar anti seize compound - be careful to not get any on the sensor head. Have fun.
Cheers.

 

Dear All,
I've just had another batch of these brackets made, taking the total production to 230. If anyone wants one, then please email me directly. andystodart@metronet.co.uk

 

Andy's bracket arrived in NZ today, 4-5 days from UK
I fitted it in about 7 minutes - I was really lucky, no seized bolts, and I am left handed so easy to work from the left hand side of the car
I put a few drops of Briggs & Stratton 4 stroke mower oil (40W viscosity - I use it in my old bicycle Sturmey Archer hubs) on each bolt, and did them up again just tight enough (used 8mm spanner and 10mm socket, shown with old bracket). it amazes me where you can squeeze an iPhone...

Thanks Andy!

I will post feedback on here when I've had a good go with the bracket using both 95 RON and 98 RON petrol..

- 2 hours later -

with 95 RON, just done two 'standing start' acceleration runs past the 70mph mark:

pre-bracket - average 10 secs 0-100 km/h (max G= 0.46 twice)
post-bracket- average 9.3 secs 0-100 " (max G=0.49 twice)

this is using Dynolicious on my iphone. Same road, similar weather and ambient temp, same tyre pressures, same fuel. So pretty close conditions.

I will post the times once I have a new tank of 98 RON

 

Great review...thanks for the figures.

 

To Johnyb60. I changed the two sensors - my car originally came from Singapore and they only have the two downstream lambda sensors. The car was running smoothly enough although clearly very rich, but an OBDII diagnosis showed that one was giving quite odd and very inconsistent voltage readings that made little sense.

 

Would I be right in thinking that this bracket will be entirely compatible with my LPG powered 4.0 litre aj6?

And can anyone tell me if I am right when I remember that my 1988 3.6 engined car seemed to be both faster AND more economical than any of the 4.0's I have since driven?

Yes, I know I shouldn't drive a Jaguar if I care about the cost of fuel, but I LIKE the XJ40 more than any other car I can reasonably expect to drive.

Cheers, Steve C.

 

My bracket works particularly well in conjunction with LPG because it has a higher octane than gasoline. I very much doubt that a brand new 4.0L Jaguar was slower than a corresponding brand new 3.6L model. No OEM could justify such a "backward step". real world fuel economy is another matter. It depends very mcuh on how the car is driven.

 

Good to know.

I perhaps should have said "quicker" rather than faster, the 3.6's felt more "alive" to me during spirited driving and definitely more economical over the long term.

HOWEVER, I've not made any measurements nor tested under controlled conditions, and as we all know engineering knowledge beats "opinion" in a fair fight.

Bracket looks like it might be just what I need, but one question.

If one advances the timing is there a greater chance of those small inlet manifold explosions re-occurring (only when on the gas) that I had when my HT loom expired last year? All the HT components were a bit sad looking so I fitted a new rotor arm, distributor cap and loom and that seems to have fixed it. Odd thing was it only backfired when I was accellerating...

I don't want that to come back at any price. Normally when I am accellerating I'm at my most heightened state of "awareness of danger" (or the police, traffic cameras, pedestrians, other motorists), and when you are concentrating furiously what you don't want is your Daimler to go "BANG"! really breaks the mood that does...

Cheers, Steve C.

 

Check out what AJ6 Engineering THE JAGUAR AJ6 ENGINE - 3.2, 3.6, AND 4.0 LITRE / AJ6 Engineering says about the airflow meter being the induction constraint on these engines.

 

Wow, I've never heard of AJ6 Engineering until your post. Many thanks! Their products look very interesting. A bracket plus a better exhaust sounds like a nice simple way to a better performing car without a major amount of work.

 

Received my bracket today and must say the install is painless. An 8 and 2 10mm bolts and an arm under a hose and its all over. Definite difference in general pep in the step in my rather short test drive.

 

Installed my bracket yesterday. More smiles per mile indeed. Definitely improved throttle response. I cannot speculate on horsepower increase and fuel economy will take a couple of tanks of gas.

 

Thanks to Dan and Mitch for their positive feedback. I have 8 brackets left from the current batch that I had made. If anyone wants one, then please get in touch (andystodart@metronet.co.uk)

 

Andy,
my 3.2 is much happier with your bracket, now on its 3rd tank of 98RON -
good acceleration, running smoothly. It needs another 0-60mph timed run on the iphone 'Dynolicious' app.
The car is currently in getting a new water hose (old one slow leak and all soft and squishy), and a new set of front suspension bushes +/- ball joints to sort out 'wander'. Next move may be a new set of 225/65 x16 tyres - winter is coming Down Here