Hi all. I have an s-type 2000 3.0 with a problem of high fuel consumption and hard engine operation. With oxygen sensors connected, short-term corrections can hang at -36 +42 highs, while one bank at +42, the second bank at -36, then they can change vice versa. Also, the readings of the lambda probes hang either in a lean or in a rich mixture. From errors p0133, p0153. RPM fluctuates at idle and the engine shakes. When the sensors are turned off, the engine operation becomes better and there are no errors and the cheсk is off. Sorry for my English, i'm from Ukraine)
What was done: removing lpg from the previous owner, adjusting valve clearances, flushing injectors, replacing intake manifold gaskets, replacing spark plugs, replacing part of coils with visible cracks, removing cat and installing flame arresters, euro-2 reprogramming. Before all these procedures, work on gasoline was just as tough, on gas it worked a little better.

 

Sounds like a pretty significant air leak somewhere in the intake to me...

Have you checked for this... ?

 

inlet gaskets replaced with new ones, no leaks, checked by a smoke generator

 

 

 

OP: "inlet gaskets replaced with new ones, no leaks, checked by a smoke generator"

Okay, you might want to have mentioned this in your initial post to avoid having us play guessing games...

What other recent repairs/diagnostic work have you done?

 

Done!

 

What do you mean by:

installing flame arresters

and by

euro-2 reprogramming

If you don't have the standard Jaguar PCM program and/or if you have changed the exhaust you probably are in trouble. You also need the correct O2 sensors in the correct places, with correct catalytic convertors.

 

OP: "What was done: removing lpg from the previous owner, adjusting valve clearances, flushing injectors, replacing intake manifold gaskets, replacing spark plugs, replacing part of coils with visible cracks, removing cat and installing flame arresters, euro-2 reprogramming. Before all these procedures, work on gasoline was just as tough, on gas it worked a little better.

Generally speaking, removing the catalysts will result in significant issues with regard to how the engine runs. You may also have diagnostic trouble codes which are not reflected in the above images as the necessary system flags have not been set in the PCM.

A liquid propane conversion, together with the reversal thereof, opens a whole different can of worms... We do have a member or two who have done this conversion and hopefully they will join the discussion. With regards to the "euro-2" reprogramming, I suspect most of us are clueless on this one...

 

I'll try to be more detailed: removing catalytic converters and installing "strongers" instead of empty barrels. The reprogramming consisted in software shutdown of the second oxygen sensors. The first sensors are in place, and are determined. All the symptoms with shaking engine and high consumption were even before all these procedures, even before the removal of lpg.
I also measured the pressure in the fuel rail today, it was about 2.7 bar, the same value is shown by my diagnostic scanner. It practically does not change even in the course.

 

I think your best course was to have done no changes except to force petrol on (lpg off), then get it working properly before any of that other non-standard stuff.

If you can go back to that, do.

 

Thank you. The removal of catalysts was a necessary measure, as they crumbled from operation on lpg. One barrel was generally empty, the second was a handful of crumbling catalyst propped up with an iron washcloth (the last owner is an idiot). It was not possible to find and install native catalysts. This is a fairly common practice for us, removing particulate filters, catalysts and egr, followed by flashing, stage 1 type, even on more modern cars. At the expense of reprogramming, I'm sure in principle that everything was done normally, as it was done at a specialized station.

 

Perhaps there is still room to dig, so the problem has not gone away after all these manipulations: with the oxygen sensors disabled, the engine runs smoother, and the check does not light up. I have never seen it at all the moment of possession, although the lamp is working.

 

That pretty much says that you’ve got some tuning issues. I think those earlier cars use those second O2 sensors for fuel mixture adjustment so turning them off might be part of the problem and who knows what the tuning is as we said it’s best to always change one thing at a time unless you’re putting in a kit that’s matched to the tune you’re installing with it, or else you don’t know where to start. Btw my family is from ukraine back in the wild west days. I think hungary has that land. Bukovina was listed as the birthplace of my great great grandparents and grandparents

 

Ive had LPG on mine cause this is my car here where im currently living, in romania.

but before that:
- is compression ok?
- i bet you reset the car bu disconnecting battery for 30m?
- did you swap your O2 sensors (in btwn left and right)?
- did you smoke test the intake and exhaust?
- are you catalyst free on both sides?

Make sure its not a crazy vacuum leak in either the intake or exhaust(pre lambda sensor) or a crazy sensor itself.

if LPG is installed correctly it shouldn't bother your car, especially a 2000 model which does have a fuel return. If its uninstalled correctly same.

Some installers are maniacs and they damage your harness when they tap in to get:
-O2 readings
-All injectors for pulse readings and killswitch
-One coil for RPM reading
Again, Maybe your harness was damaged.

 

Thank you, from all of the above, did not check for exhaust leaks. By the way, a strange hiss is heard from the engine during operation, but the smoke generator did not show anything. I also noticed strange clicks from the left head, which disappear after the first revving in gear. lpg removed, wiring restored.

 

Thanks, I'll talk again with the guys who reflashed the ECU. It's great that you know the history of your ancestors)

 

Worrying.

 

the hiss must be a pulley.
i actually dont think an airleak would cause so much trouble.
did you check the compression?

 

I may have missed something but you need to focus on what codes the car is throwing?
Keep reading and then erasing ALL codes. The two you posted are O2 sensor codes so your looking in the right place.
Please post JUST the code itself. The many pictures are very confusing trying to find all the code numbers.

Note you show numerous U and B codes. The U codes are network related which means wiring problems or more likely weak or bad battery? How old is the battery? Any chance you can swap a new one in to test?
B codes are body codes which should NOT have anything to do with the engine running badly?

When you did the smoke test was ALL of the plastic intake ducting in place? This is a very likely place for a crack or hole in the plastic to create an unmetered air leak. This will cause exactly the problems your having?
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