Gilbertd wrote:
Shake at idle could be down to it idling on 7 which would cause the problem in the first place. Do you get any P030x fault codes logged? If you do that will tell you which cylinder is misfiring. If not, while idling get your rubber gloves and a big insulated pair of pliers out and try pulling an HT lead one at a time (at least bank B is easier to get at). The one you can pull off without the idle changing is the one that isn't firing. If you put your nice new plugs in, then you've got a good baseline to start from. If you can still pull a pluglead off without the idle changing you at looking at the HT lead then. The ignition coils are paired so if one of them had failed, you'd have 2 cylinders not firing (one on each bank).
It might be that you have cured the problem and the adaptive values need to be reset (setting the long and short trims back to zero) so until that happens it is still going to run rough. If you don't have a method of resetting them (Nanocom, Faultmate, Lynx, etc), the only thing you can do is drive it and let them reset themselves. You will be looking to see the Bank B lambda sensor going fully rich (1V or at least higher than 0.5V) and the short term trim on bank B going permanently negative as it tries to lean the mixture off. If the short term trim is permanently negative, the long term trim will start to drift down to get it back where it should be.
At least you live in a civilised country though https://eandt.theiet.org/content/articles/2017/01/paris-bans-old-polluting-diesel-cars/
Hi !
No P030x codes. Only Bank B too lean. And sometimes P0150 stoichiometric ratio outside operating band
I can get my hands on a nancom to reset the values. However, without a nanocom or else, how long does it take for the values to readapt ?
Do I have to carry out all drive cycles and that's it ?
I thought about the coils initially, but with a friend's nanocom we didn't see any misfires...
Leads, why not. They're only a year old, but I did have a heating incident this summer, air in cooling system and boom bubbling on the highway...Leads could have been damaged ...plugs too maybe...
The loss of performance, both on petrol AND LPG is pointing towards the plugs I think...
I think I'll put in the new plugs, drive, and check the voltages...
Yeah they're funny with their new badge system. 0 is hydrogen and 100% electric, 1 is hybrids, LPG, 2014+petrol. And so on until 5 pre 200x diesels... Funny thing is my overfueling bird killing 7MPG LPG equipped P38 is rated 1 !
It does confirm you do indeed love wine, so access will be granted to you.
Back to the issue at hand though, I'm starting to think the following:
-before I disconnected the LPG wires from the 02s' signal wires, I never had a voltage above 0.1. Now as you can see it technically can go up to. 6V which leads me to that conclusion :
The LPG did mess up the signal, and now everything is working as it should. However, the plugs being foul on bank B, some air is not burnt etc... Leading to a lean condition seen by the sensor and gas in the exhaust. As well as poor performance and a bit of a shake at idle..
Thoughts?
And you're welcome in my bar anytime, so long as you like wine !
RRHSG wrote:
Gilbertd wrote:
The fact that the readings are permanently low and when disconnected you get an error saying it isn't detecting it would all point to a dead sensor even if it is new. Presumably you didn't get time to swap them? Either that, or knowing how cold it's been here today and that the Paris weather is usually much the same as ours, it was too bloody cold!
But, the values from TORQUE look odd. The Lambda sensor outputs for bank B look how would be expected with a dead lambda sensor, as do the long and short trims (both going very rich), but why is bank A going fully lean? Do you have any means of resetting the adaptive values?
One other thought, is it running on all 8? If one cylinder on bank B isn't firing, the air being drawn into that cylinder isn't going to be burnt so the O2 sensor will see far more Oxygen than it expects (as they only detect Oxygen and not fuel) and assume a lean mixture. That will make it throw more fuel into the cylinders on that bank. So as well as having one cylinder being fed with fuel but not burning it and spitting it out of the exhaust, the other 3 will be getting far more than they want so the excess will also end up in the exhaust. Result will be poor economy, rough running and a smell of fuel in the exhaust. With 3 cylinders running very rich it will be running so rough you may not even notice that one cylinder is doing nothing. Spark plugs and leads would be the likely cure here.
Just noticed the word bar. That gives me an excuse to take the westerly route on the Periphique when I'm next driving down south. Although looking at the map, on the one occasion I went to Versailles, I parked up just around the corner (while the girlfriend of the time went to look round the gardens).
Yeah It was about - 2°C today...pretty cold to be fiddling with wires in the engine bay outside the house ! And definitely way too cold to get under the car and touch those freezing pipes and sensors... eheheh will do as soon as temps get above zero !
It does look like a dead O2...I'll switch em and see.
Obvisouly I checked the plugs (yet not the leads...I did however test compressions on all 8, all good).
On bank A sparkplugs are good. On bank B, they're black...like nasty dirty black...so I bought some replacement irridium NGK. I was just waiting to see of the problem was related to the wiring before putting them in as I didn't want to destroy them....
And I still don't know whether the foul plugs are the cause, or the consequence of something else... !
God this is annoying (although I do enjoy the diagnosis part of things)
Cheers
Gilbertd wrote:
The fact that the readings are permanently low and when disconnected you get an error saying it isn't detecting it would all point to a dead sensor even if it is new. Presumably you didn't get time to swap them? Either that, or knowing how cold it's been here today and that the Paris weather is usually much the same as ours, it was too bloody cold!
But, the values from TORQUE look odd. The Lambda sensor outputs for bank B look how would be expected with a dead lambda sensor, as do the long and short trims (both going very rich), but why is bank A going fully lean? Do you have any means of resetting the adaptive values?
One other thought, is it running on all 8? If one cylinder on bank B isn't firing, the air being drawn into that cylinder isn't going to be burnt so the O2 sensor will see far more Oxygen than it expects (as they only detect Oxygen and not fuel) and assume a lean mixture. That will make it throw more fuel into the cylinders on that bank. So as well as having one cylinder being fed with fuel but not burning it and spitting it out of the exhaust, the other 3 will be getting far more than they want so the excess will also end up in the exhaust. Result will be poor economy, rough running and a smell of fuel in the exhaust. With 3 cylinders running very rich it will be running so rough you may not even notice that one cylinder is doing nothing. Spark plugs and leads would be the likely cure here.
Just noticed the word bar. That gives me an excuse to take the westerly route on the Periphique when I'm next driving down south. Although looking at the map, on the one occasion I went to Versailles, I parked up just around the corner (while the girlfriend of the time went to look round the gardens).
Yeah It was about - 2°C today...pretty cold to be fiddling with wires in the engine bay outside the house ! And definitely way to cold to get under the car and touche those freezing pipes and sensors... eheheh will do as soon as temps get above zero !
It does look like a dead O2...I'll switch em and see.
Obvisouly I checked the plugs. On bank A they're good. On bank B, they're black...like nasty dirty black...so I bought some replacement irridium NGK. I was just waiting to see of the problem was related to the wiring before putting them in as I didn't want to destroy them....
And I still don't know whether the foul plugs are the cause, or the consequence of something else... !
God this is annoying (although I do enjoy the diagnosis part of things)
Cheers
Ah, and I forgot, when I disconnect the sensor, the voltage drops to 0.00V and I get a code (forgot which one) that says "02 sensor, no activity detected). So that's good.
HI all !
Did a bit more testing today.
I disconnected the wires from the LPG ECU that were soldered onto the signal wires coming from the lambdas.
Voltage from sensor A does vary correctly. Sensor B however...did go as high as .6V (which is new!), but then it drops back down and stays down...as show on the graph below.
(all my files are stored on my bar's website. 100% safe I promise :-) )
And here is the values registered with TORQUE, let me know what you think !!
Thank you all !
So in order :
It's freezing today so I'll wait for tomorrow though.
Dijon is a bit far, I'm in Versailles (10 miles from Paris)..about 220 miles from Dijon
This is such a frustrating fault...A stupid electric fault on a perfectly working car making it useless...... Damnit
How stupid of me not to have thought of swapping the sensors...
Will do tomorrow.
I will also disconnect the LPG wires. If for some reason indeed there's a problem with the wiring or even the LPG ECU, this could be the cause.
I'm a bit of a tu*d with everything electrical... So, when I unplug the sensor should I be looking for a drop in voltage to 0 or hope it stays at. 04?
Also are there any checks or tests that can be performed while the car is off? I wouldn't want to ruin my cats (3000 miles only!)
Thanks a lot for replying!!
I forgot : rover is a 99 4.0L Thor equipped with a Prins LPG System.
Only 2 precat 02 sensors, nothing post cat.
And the LPG computer in the engine bay has 2 wires soldered directly on the 02's signal wires about an inch before the engine ECU.
Hi all,
After opening a thread on rangerovers.net where I got absolutely no replies whatsoever, I was advised to come here and talk to you about my P38's issues !
So let's hope I'm in the right place !
I noticed a very poor mileage, loss of performance and unburnt petrol (and its smell) spat out of the exhaust.
Hooked up the Torque android app, P0174 - Bank B too lean.
Yet my P38 is overfueling badly and therefore running extremely rich (trims at 25 on bank B, constantly enriching to the max).
I changed the 02's, nothing changed ...(they had about 70k miles on them so...couldn't hurt anyway)
I check the voltages, Bank A does vary between .1 and .9V, bank B stays fixed at 0.04-6V so very low...
I'm suspecting that it's a wiring issue.. shorted wire etc...
How can I test the wiring harness ?
Thanks a lot !
Vico
