Thanks Lpgc for that description! That helped me understand it even better than the first time.
I have 2 different Denso MAFs. The second one with all the numbers is the one purchased from Land Rover. The 602 came with my latest Rover purchase. No faults, but i have not driven if for more than 10 miles twice so i cant vouch for it
pics
https://drive.google.com/file/d/1-h9afo65nHN4TrMnQuhdKPfUD9UeJirE/view?usp=sharing
https://drive.google.com/file/d/1QiBm2ANPU_VkmL5mDR2RIXoV7j81edSh/view?usp=sharing
I will get a part # for you as soon as my wife comes back with it. I think you can get them at rock auto for a decent price
If your MAF sensors are old it might be a good idea to replace it anyway since the deteriorate over time. According to a lot of posts i have seen cleaning them is a short term solution. If memory serves the denso has the manufacture date printed on it with the part #.
Also did you smoke test your intake plenum and air filter housing? When i did mine i put a plastic sheet over the air filter and the put the cover back on. Smoke was added into the engine port at maf sensor. This could be a problem area.
It may be fuel pump related as well. Unfortunately because the pump is pwm controlled and pressure fluctuates, without knowing what the pressure and flow should be in relation to the pwm signal, there is no way to test this without throwing parts at it. (Which i hate but sometimes there are no other options.
The maf sensor seems to be a common problem associated with this code across all brands. So before replacing the fuel pump i would probably go to it first. AFTER you have eliminated any possible vacuum issues. Simply forgetting to plug the rocker cover into the intake plenum will also set set off the code.
Just a note on the brake booster. if it is bad i think it vents into the passenger compartment. So that may be something to double check.
On more thing, air filter; do not use the oil type air filters. They will contaminate and ruin the MAF sensor. I removed mine when i bought the truck but by then the MAF was already intermittently underreporting.
Ha... I hope you are not looking for me. Since i was on the receiving end of all that knowledge. But anyway, My issue was erratic, it would come and go. Sometimes without clearing faults. It turned out to be the MAF sensor. This is what tells the ecu how much air the engine is pulling in, The ecu then calculates the fuel to put in, and the O2 sensors check and force adjustments. If i understood all of that stuff correctly. One pair of fuel trims are sort of a baseline collected over time to allow for engine variables like injector flow rates etc. The other trims are used for "live" fuel calculations. (throttle, air press, engine temp) Im not sure which on is which. Together they are used by the ecu to determine how much fuel to add. But when they go out of the working window the ecu will set a rich or lean code. Obviously rich means too much fuel not enough air and lean is the opposite.
The tool i use is the IID tool I purchased online. The tool gives me the option save files as a PDF. I then just upload that to google drive and used the link in posts.
I ordered my MAF from Land Rover and they gave me the Denso sensor. So for starters i would put your Denso model in. The readings should follow the engine RPM.
The sensor voltages and numbers dont mean anything to me since i only have a basic understanding. I find the graphs much more helpful. But i can give you my 2 bits.
As for fuel pressure it is all over the place. If memory serves pressures were high 30's to low 70's. Graphs should still be in the thread, if not let me know. Depending on load, engine rpm and throttle. I was never able to find an actual pattern in it. What i did find however is, there is a switch in the fuel filter that stops the fuel gauge from reading. These are the two wires on the bottom of the filter. I assume that means the filter is plugged. But when this happens everyone seems to change the filter and the fuel pump as well. Which may or not be necessary.
Pcv valve? if i remember correctly It should only close if you blow into the engine side the rest of the time i is open. sucking or blowing on the intake side wont do it it should stay open. i think Its job is to remove fumes from the engine but to stop overpressure (major blow by) from going into the intake after the throttle body.
Any exhaust leaks before the O2 Sensors? I have small pinholes but they dont affect it. A large enough one will throw out the O2 sensors. I had to use my phone camera to get into there and take pics to actually find the pinholes.
Another question is are you in North America. If so do you have an EVAP fault. This will also cause the engine to go lean. Gas cap, evap line, purge valve etc. NA vehicles require an evap pressure test system. If not you will have to smoke test the evap system separately or try disconnecting and plugging the evap line. You may be able to do this at the purge valve.
Vacuum booster. I dont suggest plugging this one and driving on public roads. These things are extremely hard to stop with no power. Thats why there is a electric vacuum pump if the engine shuts down. But maybe smoke test it separately.
Longwinded and a little unnecessary but I Hope this helps.
Oh Yea. I forgot they changed to vortec engines in the 90s. So yea ZDDP is not needed
Im also curious if the oil manufacture said anything about running fully synthetic oils in a hydraulic flat tappet engine.
Choice of oils is really up to you. Marine technology was years behind automotive at that time. Im not sure its even possible to run a boat at stochiometric ratios since they are under full load at all times. You should definitely run oil with ZDDP in it. I run high mileage blended oils 10w30 with ZDDP additives in my marine 305 chev.
A word on the dipsticks. My boat has 2 dipsticks. One is the oil change dipstick which runs down under the oil pan and connects to the actual drain hole. The 2nd is on the other side just like a car into the oil pan. My oil change dipstick does not read the same as the one in the oil pan. It does not self level with the oil when i compare them. It always reads full. Even when it is low. Why? I dont know. I can only speculate that the dipstick may not let air in and holds a vacuum on top of the oil. Or the surface tension and skin friction in the tiny tube is to much to self level. If you have the option i recommend you get an automotive one and instal it.
It might take a bit with Christmas and all that, but I will let you know what I find
I tried swapping the solenoids from one to the other with no change. Unfortunately thats not an option with the cam sensors. I could however take the sensor out of the good Rover to test the signal. BUT:
You got me thinking about the phaser comment, and I remember noticing an anomaly while doing the timing. Before and after resetting the cam timing i noticed that when i turned the engine over the exhaust camshaft would push the intake cam at a certain points and the chain would become slack on the side that should stay tight. However during the rest of the rotation the chain was fiddle string tight. So when i retimed it and saw the loose chain again i simply pushed the guide so the tensioner moved to the next stop. That seemed to solve the issue.
Now that i have spent days watching utube vids on the phasers and learning how the system works. I suspect that the phaser was not locking properly and allowing the exhaust cam to push the intake causing the chain to loosen. And now it is timed in the wrong position which is why its throwing the correlation code.
I also found out that the engine has been replaced when is got into the job. Found a stock number on the front of the timing cover that is not supposed to be there. It is varnished on the top of bank 1 but not equally varnished on bank 2. It also appears that someone may have been in there already since the gaskets were not fully crushed like they should be for the age of the engine. This may have something to do with the phaser being out of time.
So... it looks like Im going back in. At least it will be easier this time now that I know what Im doing. I will open up the phaser to see what i find and decide from there if I clean and reinstall it or replace the lot.
No i did not. Just the sticky tensioner. Chains and guides were all left in place and looked good. I did retime the cams. I do wonder if that is the case. How do i tell if the phaser is trash?
What i dont understand and am trying to figure out is what the signals mean. With only on sensor per bank i would have thought that if the cam sensor is incorrect that the vale timing would also change. but that does not seem to relate. Its like it defaults to a single sensor and changes the timing on both cams together. If you compare the signals from the good Rover to the bad one the cam timing never moves 9 degrees like the questionable signal indicates. It only moves 0-0.4 degrees. Even the cam timing angles only move a few degrees. So I wonder if 9 degrees is even possible without catastrophic engine damage. Also when i unplugged the cam sensor the questionable signal only drops to 5 degrees and not to 0.
Could this be electrickery like a bad ground or something. I am not getting a cam sensor fault only the correlation fault. And also no chain noise since retiming the engine.
Purchased another 08 supercharged RR for cheap about 2 years ago. Did not move but ran well with crankshaft correlation fault. Front driveshaft broke, easy fix. Correlation fault, not so much. I did hear the chain rattle occasionally, But I decided it was too good to just save for parts, so in we go. Main timing chains were tight, secondary chains looked good as well. Tensioner on bank 1 stuck in collapsed position during a second look 3 days later. Replaced it and retimed the engine. Runs even better now but i still have a correlation fault. I then swapped the timing solenoids to the opposite banks to see if the fault moved with the solenoid, but it did not.
Got my gap tool out and did some comparisons with the other Rover.
"Intake variable camshaft timing" on both banks reads within 5 degrees per bank on both Rovers. "Actual inlet variable valve timing" on the good Rover both banks are the same (0-0.4). On the faulty Rover bank 2 matches the good Rover (0-0.4) but bank 1 reads 9-11 degrees.
Does this point to a faulty camshaft position sensor?
Attached are the graphs that i took from each vehicle.
https://drive.google.com/file/d/1uu8KleuSBdLJXQyMiadj7cq0-FLidDDB/view?usp=sharing
https://drive.google.com/file/d/1DqGWNU90F1wxbjdkeqgwetMbEDuHghjv/view?usp=sharing
UPDATE:
The truck has been running great, no Mil light.
Data log from last wed with the new Maf sensor.
https://drive.google.com/file/d/12HHfxZqBgnBm-A1zdWrmOHUCM-p15tYJ/view?usp=sharing
I installed the old sensor for a few days as requested and the LFTs seemed to become somewhat inconsistent, Friday they were high around 10, Sunday they were only slightly above normal and today they went up to 11-13 during cruise. Interestingly they never got as high as they were before the sensor was replaced. Which could be just not enough mileage yet. It does not seem to have proper throttle response with the old sensor. It feels slightly lame at times usually when passing cars. It feels like it takes more throttle to make things happen. But that could also just be in my head.
I do have some data logs if you want to see them. I will be reinstalling the new sensor tonight.
One more dumb question.
Short of actually drilling a hole in my exhaust, what should keep an eye on to see if the small exhaust leaks (in previous pics) are actually starting to cause trouble? ( Im assuming Lfts and equivalence ratios)
I plan on repairing them but would like to wait until winter when Im not driving the truck.
Ha ha refitting the old Maf... That's Brilliant! (not sarcasm) I glad I havent binned it yet. I will give it about a month and try that.
How long would you expect it to take the fuel trims to go crazy again?
It took the rush hour drive thru town and a few miles of cruise to see the results after replacing it. (Long enough for me to think I had just spent $450 for nothing)
The real test will come in fall when it gets colder and the air gets denser. But we may still get some cold spells yet. I did have the Mil pop up over the weekend before I got the new Maf.
I wish I had actually calculated my fuel mileage before changing the Maf, to see if it actually changed. Im not sure how the readout actually calculates it and how accurate they are, time will tell I guess.
I am a little disappointed though, I drove an hour+ one way, paid Land Rover dollars and was then handed a Denso Maf sensor. Which I could have purchased locally for half
the cost.
Oh well c'est la vie
Sorry for the slow update.
I got the new Maf sensor Tuesday night. So i did some logging in town before changing it
Before
(https://drive.google.com/file/d/1P7uLioEd1aluSqYxnfKfkvewuUksglFg/view?usp=sharing)
After
(https://drive.google.com/file/d/1F0-n0PV_FdNlk4sUieRhfmnTVwLolh-e/view?usp=sharing)
It took some time but the fuel trims did eventually come way down and I think the fuel pressure increased by a few pounds as well.
This one is after about an hour on the drive home using same road I have been doing most of my data logging on.
(https://drive.google.com/file/d/1EPTpIeFx7HYfgQrzf0WXKXcF4qtsEH0Z/view?usp=sharing)
So far I like what I am seeing, I will probably pull some plugs on the weekend to confirm this.
Maf sensor should be here tues or wed of next week
Ill see what happens. might take a few days though Its cold and crappy here still for the next few days.
Im thinking I should change the Maf anyway since it is most likely polluted with oil from the previous air filter. I need to get some exhaust gaskets anyway
Some would call that cheating. LOL (instead of trying to find everything the electrical drawing) I assume you have to cut them all regardless. Easier, faster, why not?
I dont mind buying parts once im sure they are the right ones. And this is now starting to make sense.
Ok will do
I assume you want me to log data as per your list earlier?
And I assume this should be done with engine at operating temp,
Should i do this before or after changing the Maf?