That's me screwed then

 

aholbro1's memory is spot on. Jaguar advises against revving the engine beyond 2,000 rpm with the transmission in Park or Neutral or internal transmission damage may occur.

Below is a link to the TSB he remembered. It was issued early in 1995 and applied directly to XJ40s, but since X300s use the same ZF 4HP24 gearbox the same cautions should apply:

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


Cheers,

Don

 

Jings I am screwed for sure. I suspect the Jag may forgive me.

 

Yep, ther eis a difference between what is not recommended and certain failure. If you don't hear a loud boom or grown and car still shifts yiu are probably OK. I am sure more than one of these has been reved in neutral without disaster! But don't do it on a regular basis.

 

I'm hoping the weather will be good enough to fit and test the MAF I bought.

 

I have fitted the replacement MAF, checked the Lambda sensor connections plus a couple of others which were all spotless.. Made sure there are no air leaks as best I can. There is an exhaust leak before the O2 sensors in one pipe. I found it was a little low on engine oil but I can’t see that being an issue.

On a test run it drove nicely but wouldn’t pull beyond 4500 rpm locked in second gear.

I bought Torque OBD software and it certainly detects two banks of O2 sensors but the readings are confusing. I need to look at them some more to understand what it’s telling me.

The STFT readings all look sensible at usually under +-5% although (of course) the LTFT is still way high at -98%.

Subjectively I’d say it smells like it’s running rich on idle but my investigations were cut short by needing to do some work.

I think a hard reset might help the LTFT.

The local consensus seems to be that it has the feel of a fuel problem so I don’t think I can dodge the bullet of changing the fuel filter.

Changing the water temperature sensor – well yes I think I will but I’ll have to order it in.

Oh and the transmission seems fine

 

OK I did a hard reset by disconnecting the battery for 30 minutes.

The hard reset failed to clear the crazy -98% LTFT but did reset the others so hopefully someone can explain that.

With my not at all attractive assistant watching the readings on the scanner it's quite plain that the MAF varies sensibly and 3 of the 4 O2 sensors read up and down in synch with one stuck at a practical zero. The others fluctuate between -1.5v to 4.7v which I think is normal. But Bank 1 does not.

Therefore, I think I have a dud sensor wherever bank 1 is and I'm hoping someone will tell me.

Then I have choices.

I can get a genuine part for £90
A Delphi part that they recommend for £10
Or gamble on a used eBay part probably for £10

Then either try and fit myself or more probably have the village garage do so.

I think that's logical?

Mike

 

The early 95 cars almost never give meaningful LTFT. Mine is usually about +50 for both banks. Just ignore it.

 

Thank you for that - but I assume you would replace the unresponsive sensor?

 

Yes!
Just be sure you are getting the correct Titania sensor and not a "universal" zirconium one which will not work. Bank 1 is the fron three cylinders. Does your car have two or four lambdas?

And RJ is right.

 

Mike,

It would be worth checking the electrical connector of the non-responsive O2 sensor for looseness or corrosion.

Please don't gamble on a used O2 sensor, and that price on the Delphi part sounds too low - is it really just £10?

I believe the original equipment O2 sensors on the X300 were made by NTK (NGK). You can look up the part numbers for your car at this site:

NGK Spark Plugs

Armed with the NTK part number (25018?), you can then shop around for the best price. My guess is that you'll be able to find one for significantly less than £90. For example, in the U.S. the 25018 is available at Rock Auto for USD $67 (£44).

Cheers,

Don

 

The Delphi part is listed here if you're lucky.

Delphi Online Catalogue

It's not a very nice user interface on that site. The cheap part that says it will 'work' is here 3 Conductor Delphi Lambda Sensor O2 Oxygen Probe Exhaust Genuine OE Quality | eBay

The sensor is two or maybe three wire by the look of it and you have to buy an adapter to fit the connector block on the Jaguar or I could splice.

That NGK part looks ideal but I'm struggling to find a supplier in the UK and it costs about £50. I shall search some more and ask at my local motor factors.

Will the cheaper Zirconium from Delphi 'not work' or just be non optimal and have limited life span? I am not certain that this will fix the problem although I suspect it will and really I am eliminating what I find to be wrong as I go along.

I'm not going to let this car become a money pit. I love it, enjoy driving it but I'm not spending loads of money on it and of course loads is open to interpretation

All help and advice both welcome and appreciated!

Mike

 

Zirconia sensors will not work, like not work. Wrong technology (resistance instead of voltage source!).

 

Yes, I now realise that this is the case having down some research. I will ask Delphi why they think their part is suitable I think just out of sheer devilment.

I can get the NGT item but at some considerable cost like £100. I have also located a suitable substitute from a reputable dealer at about £50.

However, I shall first recheck the wiring.

 

How about these
https://britishparts.co.uk/products/...nsor-LHE1682AA

£42 only

 

That's the one I found but it creeps up in cost as you add VAT and postage. I'm wondering if the same part isn't used on Range Rovers as I can get the parts locally in that case and usually rather cheaper.

 

I'm really confused now.

How many O2 sensors should I have and where are they located?

I can see two down beneath the engine that have leads going up to those awkward to get at connectors between the engine and the bulkhead.

the catalytic converter is presumably between the engine and the wheel arch shrouded within some this steel. Is that right. Stupidly I thought it was under the floor pan and that there would two more sensors there as well.

This is not going well as I have never worked on an engine with any sensible emissions control before.

I have seen diagrams showing two more sensors way up by the engine on the downpipe. I think these are for the Japanese market? I can't see any there but I wasn't expecting to so I may have missed them.

I am becoming fed up with the whole damned thing but it's always darkest before the dawn.

 

Mike,

I just realized that given your UK location, you may only have two O2 sensors, the downstream ones after the catalytic converter. Which begs the question, why are you getting data from three O2 sensors?

Don

 

I think I only have two sensors as you say downstream. Sigh I'll have to check the scanner again in the morning. Too dark, cold and wet now.

 

Yes Don is right. On a UK car there are only 2 sensors and they are immediately after the Primary Cat. The picture below shows the location.

There is a secondary cat also under the floor pan but it is not monitored and plays no role in engine management.