They look better than mine when I replaced them, mine were still working but very lazy, with the old ones it took 2 miles for them to switch to closed loop, with the new ones it takes ~20 seconds and they flicker between 0-5V considerably quicker now.

Fingers crossed, yours should be fine now. Keep us updated and still have a look at ECU when you get a chance

 

Thanks Katar83 - you raise a good point I will use my ODBII scanner at the weekend to see how quick the car goes closed loop, mine certainly took much more than 20 seconds in the past. I still do plan to check the ECU.

Thanks to you and everyone for your advice and support.

It is appreciated.

Cheers,
Nick

 

There was mention of a ECU orientation in the Jaguar 801S doc. on the O2 sensors ( along with TPS )as may have been done on them at the factory so it runs top notch off the show floor . But in practice the ECU may " learn " itself over a period of time with a new set . Just guessing and maybe one at a time so the ECU is not way lost with 4 new

Mileage doesn't mater if the engine is out of trim to show carbon

The sensing membrane inside the vents may be cleaned by soaking in gasoline if it has any life left but 60 K is the usual benchmark not knowing the specifics on this one .

I had a code P0140 ECT that went away after cleaning up the connector , a dirty connector mimics a colder engine coolant on the thermistor sensor

 

Hi,

My car currently is not showing an error codes, my only paranoia is the o2 sensors got that black from over rich fuelling and may not have caused the issue. I will pay close attention to the fuel trim now that the car has nice new celan o2 sensors in it. Hopefully we won't see it rising from +8 way up to 25 degrees C.

Thanks,
nickdabs

 

Did you ever resolve the issues you had ?

 

Hi X300exec,

In short yes. It was a long road and I would do things a bit differently if I went back in time. I don't live in the remote vicinity of a good Jaguar specialist and I tried to resolve the problems myself or with the assistance of a local garage who would do whatever I asked them based on many helpful suggestions from here. In the end I renewed all sensors, plugs, coils (QYL imported from the USA are great) and still I had a bad idle and oscillating revs. In the end, I thought I should eBay the car or take it to a guru for one last attempt. I took it to Tom Lenthall in Wokingham who insisted over the phone that they knew exactly what to do to sort my car. They reset up the throttle body correctly adjusting the butterfly and reprogrammed the TPS, etc. using IDS, tightened the throttle return spring and serviced the car. I have perfect idle, better fuel consumption. I even got them to retrofit cruise control for me.

X300 is sorted. I now have an X358 in my fleet and my X300 is having a little breather and looking nice in my carport. If I had gone to a genuine expert garage from the outset I would have saved loads of money and got to happy X300 Jag ownership much quicker!

Are you suffering similar issues?

Cheers,
Nick D

 

Kind of yes,

had bad fuel economy and emissions and occasional stalling at idle also wouldn’t rev over 4200 at kicdown,replaced both o2 sensors and now getting great fuel economy of over 30mpg on a good run and will now rev to red line on kickdown ,

BUT Once the temp gauge moves off the cold mark I get a wobbly idle ,almost v8 type of wobble and it’s doing my head in

ticks over perfect when cold and when fully hot also perfect ....just that intermediate period is not right....

ive replaced all sensors and cleaned throttle body and replaced with correct spark plugs correctly gapped and it’s still doing it

this weekend she’s getting an overdose of injector cleaner and an Ecu reset and the cts tested with an ohm meter,

the coils appear perfect and ove insulated them all with industrial heat shrink just in case but I’ll be testing these with the ohm meter as well at the weekend

 

Rather weird, let us know what happens after these next steps.