And to top it all off. I THINK WE HAVE SUCCESS.
I crawled under the truck to look at the O2 sensors. I found some crap welding on the pipe and the O2 bung that does not look original. It appears that someone has changed the upstream sensors since I can see wrench marks on them and either the bungs spun in the pipe (doubtful) or someone over heated the pipe with a torch and then attempted to weld the holes up. So I decided to take some pics for you guys. After some effort to get my phone in there to question this and get some pics for you, upon reviewing the pics I spotted the telltales of tiny pinholes in weld on each side that are hidden from view. And the bank1 side is slightly larger than bank 2
I have read that these pinholes can cause the P0171 and P0174 lean MILs.
Pic here.
Bank 1 (https://drive.google.com/file/d/1PcmpetTjJSRtsTDsOGYjZQY-tjkjzX3f/view?usp=sharing) A little black smile near the bottom of the weld just above the flange
Band 2 (https://drive.google.com/file/d/1Dhl-dsXqUyUJABrlr_yLFRpWX6j_ZITs/view?usp=sharing) I couldnt get the camera around the backside of the weld
This one is a little harder to see. There is a small black spot on the left of the weld right at the edge of the weld with the telltale puff heading away from the weld. and a small black spot above the weld where someone struck an arc while not being ale to see properly
Looks like i will be removing these for repair and/or replacement.
What are the odds of not destroying the O2 sensors during this process?
So I spent the day attempting to get to my fuel filter. And found a few interesting things. I must have gotten a good one not built on a Mon or Fri. My fuel filter had the manufactures seal still on the access holes on both sides. I also found that there are 2 wires on the bottom of the filter that when disconnected turn set the fuel gauge to empty. Both wires appear to be isolated from each other. I wonder if there is a switch in the filter that sets the gauge to empty if the filter becomes plugged.
I also found a date on my MAF sensor and it is the original made in Germany part with an 08 year on it.
pics of filters
(https://drive.google.com/file/d/1TXxgCue4pR6VzLQmewZq4vhQObIEQxL7/view?usp=sharing)
(https://drive.google.com/file/d/1-7LMmQKjOyW43gWkgqMW-r8PT-R4XQAy/view?usp=sharing)
Lpgc
Here are the logs you suggested. I let it idle for about 5 min and then drove at different speeds with a few hills for good measure and without cruise.
(https://drive.google.com/file/d/1gGn3xlvCLwtCL9uyUvxO9MzXJwXfzEQN/view?usp=sharing)
I also did a maf log as well for interest.
(https://drive.google.com/file/d/1pqW-K7w2iJvczzIjGXKTnL55ou48j3JZ/view?usp=sharing)
So i read something about oiled kK&N air filters fouling MAF sensors. Since the air filter i just replaced was of this type. I cleaned the MAF with rubbing alcohol and went for a rip. Logged it from the end of my driveway. Engine was already up to min temp when i started logging. I goofed and logged both the equivalence ratios but missed fuel pressure.
File is a pdf, may give you a better look. Sometimes this works but not always. If this format is preferred let me know. Ignore anything left of 0, Im not sure why my tool does this.
(https://drive.google.com/file/d/1sfPyjiuMdKU2PkrXWmU0sauC6JpkwDGj/view?usp=sharing)
I will try to remember to get those traces tomorrow evening on my way home. I was starting to think I should include rpm or load on some of these traces just for reference. 6 months from now they wont mean much to me if I cant remember what the conditions were.
I have a couple of dumb questions for to gain some more understanding
1 I have read on other posts where guys have said they changed some o2 sensors and that solved the problem. Claiming they were old and probably reacting slower than they should. Rate of response, I think was the term. Is this possible? ie reading lower and/or slower. I need a little more than someone's parts cannon to go down that rabbit hole.
2 Relating to question1 If I understand this right, disconnecting an o2 sensor should cause the ecu to go into some sort of safe mixture/map mode (open loop??? using cold mixture settings). Would this then be visible on the ignition timing, injector pulse width, fuel pressure, etc. traces for comparison. And also visibly on the plugs as a richer setting?
Those heavy anomalies are going downhill while using cruise control. It does this when the throttle is closed until the speed is reduced to a certain point. (quite slow or until brakes/throttle applied). My interpretation of this, is that they want the fuel pump to have reserve pressure in case of full throttle application. This makes me believe it is a pressure command to the pump control unit. For that reason Im also in most cases trying to do all my data recording on the same stretch of road for comparison purposes while physically watching things at other times.
I will see what I can get. I am limited to max 8 traces at once and this does slow down the read rate but should still be good enough. On Sunday when i go to town I will get some varying conditions. Should I be monitoring this stuff when the engine is stone cold as well? I would think they would have allowed some extra fudge factor for cold conditions.
One more dumb question I see on other sites some discussion about ecu reprograming/updating. Is this something i should get done? If so dealer item i assume? It has about 230 000km on the clock.
Just a note. I still have not seen the lean code since i last noted it in this thread.
Actually the fuel pump doesnt look that bad. It does follow the fuel pump percentage line. This is also a PWM controlled pump, so the pressure will go up and down according to what the controller gives it. What does bother me is the amt of sawtooth in the pattern considering the smoothness of what i assume is either the PWM signal itself or the commanded signal to the control unit. Also the manual calls for 45 psi at idle, It might be averaging 45 psi but it falls to as low as 41psi. and not smooth.
FYI
So just for sh#ts and giggles, (Canadian slang for -- because I can) I decided to test if my EVAP system is operating correctly. I loosened my fuel cap after driving. It took 3 starts to set, but it did set an evap MIL. It even stated on the dash to check my fuel cap and that i had a large evap leak.
So that eliminates another possibility of a vacuum leak in that system
I wondered about that. At least i have some sort of data to look back at when this fault finally shows up again. Which im pretty sure it will..
Lpgc
Bear with me I am old enough to remember carburetors, points ignition and days long before electronic fuel injection. Fuel injection is still a new learning curve for me. I only have 2 options, learn new technology or take it in to Land Rover and hand over my first born male child, The latter of which does not appeal to me.
I have only uploaded pics of data snippets. Equivalence ratios are included. Some of the data I am looking at may not be relevant since I have about 6 different ways to read information from O2 sensors. Im not entirely sure what data I am looking at yet. Also I am old and my eyes are not as good as they used to be. Sometimes i have to look at it 3 times to realize what I am looking at on these tiny cell phone screens. ( And as with most of us, I can shoot my mouth off before fully understanding it). At this point I am certain this is not a vacuum leak and fairy certain it is not a sensor issue. The equivalence ratios are very close to the commanded ratio. Fuel pump pressure (to me since I have no reference) appears to be slightly weak but reasonable. The fuel trims seem high to me albeit Im not entirely sure what is considered normal. I am trying to follow the general procedures for this code. Vacuum leaks test first. Passed. Check sensors and look for anomalies. So far so good.
Other than fuel trims all seems to be fine. I have put some data up for viewing. If you would like me to look at something specific, If it is within my means I would be happy to try to obtain it for evaluation.
I do believe It is sailing close to the wind on both banks, at this point I am mostly data logging to build a picture of it should look like. So that when the MIL shows up I have somewhat of a baseline. And I can then figure out where to look further without driving myself into the poor house by just throwing parts at it.
As i understand it, the O2/ lambda controls/adjusts fuel trims until the fuel trims exceed their working window. Which then sets in my case a lean MIL.
Things that affect the lambda. Vacuum leaks, bad O2 sensor (which should set another/different MIL) and fuel delivery.
Have I understood this correctly? If not please correct me
Injector cleaning fluid used was Seafoam added to the fuel tank at the highest recommended strength
Swapping parts has crossed my mind but O2 sensors are particularly tricky. Quite often they fail simply by removing them. And im not at all convinced the O2 sensors have anything to do with this. They appear to be doing their job and compensating for something. Besides when they fail they are supposed to set a MIL. I did some more logging today on the fuel pump pressures and fuel trims. The long term fuel trims are near the top end of what I understand is acceptable, 16%for bank 1 and 13% for bank 2 at 110 kmh cruise. With bank1 compensating slightly more than bank2 on deceleration and acceleration. I will upload some more data pics.
In all the data logging I have done the only thing that really stands out (as I learn how to use this tool of course) is the both long term fuel trims. If both are higher than they should be with I suspect bank1 setting the MIL when it crosses the threshold, and bank2 not far behind. To me that seems to indicate fuel starvation but on both banks. Since the fuel enters the rail near the pressure sender at cyl 8 then crosses at the front of the engine to bank1 cyl 1 It makes sense that slightly low pressure/flow would cause bank1 to cross the threshold before bank2. And just to make things interesting, its sits just under the threshold until things get cold.
Am i making sense or is it beginning to sound like im overthinking it and spewing gibberish?
Yea Im not entirely sure what im looking at. The other weird thing about this is that bank 1 is actually the problem bank and the one associated with the MIL code.
Some of the pattern may have to do with the data rate on my scan tool/analyzer. .
I still think this comes down to a fuel delivery issue since it does not affect all the cyl on one bank
Still thinking about some ideas to test this theory.
(https://drive.google.com/file/d/16md9xZX8RSnbZ-ZMjBr4QX37JwufLOtg/view?usp=sharing)
Here you can see how bank1 is slightly more aggressive on lambda and O2 equivalence than on Bank2
(https://drive.google.com/file/d/1zhrqGf6ShIoYejgzuh0371MPJlkw1sDA/view?usp=share_link)
Here you can see how the bank1 sensor does not match bank 2 sensor readings. I mistakenly thought they were reading volts. Im not sure what "s" means. (secconds???)
davew
There are 2 sets of pic from the plugs the first set cyl 1,3,5 look slightly on the lean side. You can see quite a difference in the second set of pics. Between those pics i have done nothing to the truck other than 3 cans of fuel injector cleaner. An obviously we have spring temps instead of winter.
but whatever is throwing up that MIL is obviously only slight/intermittent so may not even be particularly visible/obvious like that anyway (?) There remains an imbalance/anomaly somewhere but -at least for me- it is seems inherently more electrical than anything else (?)
I agree. There is something at the tipping point of failure. Its just does not want to fail and the ecu is able to still keep things within the specifications.
when the temps are warmish. So at this point i need to eliminate all mechanical elements and get an idea how this system works and should look. In fall when it gets colder i have a pic to compare too.
The only thing left before going down the electrical road, is to check out the fuel system. Since the pressures seem to be OK, That leaves only the flow. It is possible to have pressure without sufficient flow, which would create a lean code. And as seen in the first plugs reference pic, not all the cyl on the same bank are lean.
I assume that the ecu uses #1 cyl for ign and injection timing. And since #1 cyl is one of the affected ones. I wonder if this is a result of min pressure, low flow and/or slow response time. This would also get worse in colder temps since the fuel becomes denser and harder to move.
The intake air temp does generally follow the ambient. This truck has an IAT sensor in the manifold and because of the supercharger it tends to read higher depending on how well the intercoolers can cool. When it is cold it is usually very close to abmbient. I was looking to see if the maf can be read but havent found that yet.
Uploaded another graph of the maf sensor
(https://drive.google.com/file/d/1t78IKUXwN8AxDLMv42ZNQWYf3i9jCNrW/view?usp=share_link)
Since all eight injectors are very close together in pulse length as per my data logging. Im pretty sure that a loss of compression would create a rich condition. Which is not what the plugs are telling me.
p73990: Still not sure why smoke is not coming out the tail... !
Have you tried pressure tests on the pots since the plugs look better now (ie. except for one) ?
Again any slight leaks could certainly be temperature-related yes
No smoke out the tail because there is no cyl with both valves open. This makes it easier anyway since i can then generate some pressure to force smoke out. Bumping over the engine is not an easy option since since i would have to do it directly from the starter. It has the self start on it. Besides if i want to test the exhaust its easy enough to plug them while running
I have no idea what you mean by "pots" If you are referring to a compression test then no, I cant see compression being a problem since there is no oil in the pcv and it runs way to smooth.