The Car Nobody Could Fix Pt1
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- Опубликовано: 3 окт 2024
- Owner of this 2012 Honda Odyssey has been trying for 3 YEARS to get car correctly diagnosed and has spend over $4000 try to get it fixed but nothing has worked.
Car has unstable idle, hesitation with acceleration and poor fuel economy with NO CHECK ENGINE LIGHT CODES!!
Can we solve the mystery?
Part 2 is HERE: • The Car Nobody Could F...
In-Cylinder Pressure Diagnostics Video is here: • How To Check Valve Tim...
Get tutorials on how to do basic diagnostics at my website:
www.schrodingersboxqm.com
Came for the artwork, stayed for the education! Love the thought process!
It's commonly known that the valve clearances on Honda V6 engines tighten up over time and cause issues. It's surprising that all the mechanics before you failed to check for this issue. Good job!
Especially as it is on the scheduled service list!
My blood pressure went high when I heard how many parts those "mechanics" replaced on this engine. Even more so since it is a Honda. You do well, Matt. 👍🤗
It is if they aren’t any better than the existing parts because then it’s just wasted money. New parts that aren’t needed make the owner feel better, but not the car.
Very interesting! As a former air-cooled VW mechanic, I know valve adjustments are very important. And now to visit part 2.
Ive done this adjustment a few times on my classic beetle and bmw moto. Not for this reason but for routine maintenance….. because the book said so. lol
Nice case study! I believe these have no cam phasers and the valve timing is changed solely by engaging the 3rd rocker arm (VTEC) Surprised no one thought to adjust the valves which actually is a job that is "needed anyways" after a certain amount of miles.
every 100k for my old Element V-tec
You would have thought valve adjustment was done when timing belt was duh huh I r maybe they did it but not correctly that MN are it seem like problem was not fixed
Extremely informative. Broke down loss of power whilst trying to accelerate - Garage diagnosed MAP problem. Pipe blocked with carbon including connection into manifold. This video so helpful. Going to take a look at readings using volt meter
Do a running compression check to see volumetric efficiency of the cylinders. You could also put a vacuum gauge on the engine and analyze the movement of the needle. You have the hood prop in the service position. There is another hole that would allow you to remove the fuse cover.
Low compression would yield a LEAN condition on a MAF sensor vehicle.
Running rich - that's at least some symptom to put your hands on.
I have seen the opposite - running lean condition code and that was the MAP sensor, but the ECU didn't have a fault check for the MAP sensor. But driving the car revealed a situation similar to a lean carburetor.
A nice idle is also a good start, it makes things a lot easier.
My truck had a high idle issue. I checked all my sensors. Found nothing. Replaced no parts. After 2 years it went away. My theory is it must have caught COVID since COVID mainly effects your respiratory system aka my truck was breathing hard, causing a fast idle
One of the Drs I work with, his wifes car broke. He said it had covid. Broken valve spring, so yes respiratory😅
Actually, if your truck had covid it would run rich because it was lacking oxygen and it would have poor performance above idle 🤣
@@tonyt1554 true. I did find one issue that would cause a high idle but it fixed nothing. I was doing the ole carb cleaner spray on everything and when I got to the back of the throttle body the truck straightened out. I found it had a crack/hole in the intake manifold. I replaced it and it helped nothing. After that I left it alone. Checked all sensors and nothing. Being a 91 Silverado it didn't have many sensors. All tested good but I should have replaced anyways, right? Hahaha. But it's running good these days. I love driving it
Thermostat?
🤣🤣🤣🤣🤔
Very intelligent way to troubleshoot and diagnose them A.K problems that 99% fail because they get overwhelmed and frustrated after they start with most commonly replaced part that is the part that resolved them symptoms . Reminds me of how I have seen my dad diagnose engines back in the. 60"s and I still use a basic vacuum gauge inmy diagnostic procedure that will help you know what the engine vacuum should be at certain given conditions and how the exhaust smells as a SWAG on the fuel ratio and just by watching the gauge and seeing the vacuum and ne needle fluctuations tells you what is happening with the engine and the component that causes the gauge to react like that while engine is running at the condition of your diagnostic procedure enjoy your videos and I am always learning when I see different ways people use to troubleshoot some things you don't use and sometimes you can see the difference ways that several people used and take all them and b are a better way that works for you
Mat, it is just a pleasure to watch your videos and learn from you. Thank you very much.🙏
Happy to hear that!
Manufacturers really need to get on board with in cylinder pressure transducer diagnostics. Give us specs for valve timing or just flat out give us known good waveforms. I mean we’ve been using pressure transducers for years so it’s about time they recognize it for the powerful tool it is.
Agreed!!!!
This is an excellent video example of the failure of the whole electronic aspect of vehicle maintenance and complicated evolution. You have a vehicle with a years-long issue and yet there are no trouble codes. Has vehicle maintenance become easier? In a lot of cases there is reason for satisfaction but every so often you get this type of case. It should not be so.
Had same issue but with a pilot!
Problem was clogged catalytic converter!
Hello from California 👋
I hate it when they dump extra platinum into a catalytic converter. 😁
no doubt he is a master great case study definitely is going to be fix on part 2 can wait thanks master
Thanks for watching!
Your moments of humility are a great balance for all your knowledge. Awesome video!
I appreciate that! but I don’t think most people would compliment me for humility lol!!’
@@SchrodingersBox It shines through, I see it. I know you can be brash toward trolls, too- but they have it coming! LOL
You should do in-cylinder graphing of the compression. You can do running and cranking. You can measure valve timing in minutes. If you valve timing is off it the adjustment is off you can see it.
I think I would have started with a cam crank waveform and compared it with known good. Never know when you may have a bet off a tooth or two or have a sheared keyway, but in-cylinder pressure will tell you too if you have something opening at the wrong time. I made my own pressure transducer, and it has come in handy a few times.
Yep that’s what I initially did and upon finding timing was correct I ruled out timing. but then when I also ruled everything else out I had to revisit it.
Cam lobe has likely shifted on the shaft.
Cam lobe shifted???! What data indicates that??? I only see data showing that cannot possibly be the issue.
Very informative..the best teacher and diagnostician
Nice study case sir. Many thanks to this channel as it helped me to pass (1st place) Motor vehicle electronics with a merit🤗. Am grateful for the free subscription as well🙏🙏
Well done! glad to hear that!
Hood is in the "service" position(opened a little more than just an oil change), if you move it to the other position(hood is closed a little more) you can open that fusebox easily/easier
OneLeggedHondamechanic said, on a warm engine at temperature. the MAP voltage should be 0.85volts and that higher values can indicate tight Exhaust Valves.
A pulse sensor ( like first look or Cody’s) in the exhaust will show the need for a valve adjustment especially on that engine. Brandon Steckler has a book and free uTube class that actually has a case study on that exact engine. Your pico pressure transducer will also work in the exhaust although I think it might be inverted
Yes i saw his cylinder pressure analysis video- it’s how i learned to use the transducer in fact. Didn’t know about the exhaust trick though- I would have tried that had I known!
cool video, i enjoyed it for my lunch break. i'm excited for part II
Everybody always skips the valve adjust. 210k service (timing belt, water pump, spark plugs AND valve adjust).The shop that replaced the timing belt was looking for easy money and didn't follow the recommended service interval properly. Surprised the HONDA dealer didn't look at the valve adjustment as a possible performance and drivability concern.
Sounds like 'credit card engineering' by the various garages ! On Honda VVTi engines there may be a tiny mesh filter near the cylinder head which can become clogged and is a replaceable item..
I had a Honda CRV Come in with similar issues. Tuned out to be the Cat and REAR O2 sensor. Took a long time to figure out because in school I was taught the rear o2 is only for cat. monitoring........not the case anymore, it actively changed the fuel trim!!!!
Yeah that would have been a tough one! Yes since the early 2000’s cars started using the rear sensor for some fuel trim adjustment, not just cat activity.
It appears that since the introduction of wide band O2 sensors that catalyst monitors can now effect A/F ratios. Yes it was a hard learned lesson.
Valve lash affect timing. Valve guides seals or with 200,000 miles valve guides. Does it burn oil gonna be stuck rings. Or is Walter Matthau said in the movies carbon on the valves affects the billing for the valves to close and could run rich. Let’s watch part two and see
The parts changer voice always gets me, always!!! 😊
Hahahah. that’s what I figure they sound like. another viewer Andy call it the “asshat voice” lol
@9:22 That Firebird Symbol 💪💪
Hahaha I have them everywhere!! I love love love my trans am!! ❤️
10:00 Long Term fuel trims were absolutely stuck at - 8.6 and never made any adjustments at all.. So something is fishy there to me-- I've never seen them stay stuck and not fluctuate at least a little bit. ?? I'd definitely want to look at the 02 sensors with a scope and/ or a scan tool and see how they actually graph.. I wouldn't trust any of those parts just because they are new. Generic parts fail right out of the box all the time. Especially precision sensors like 02 and MAF sensors.
previous total trim was minimum neg 16 on average with range of neg 14 to Meg 21. Now LTFTaverages neg 7 with STFT at +4. no doubt about it- there was significant change in fuel trim. And it continues to adjust towards positive as well.
obviously it is relearning specific cells which is why you see STFT at zero for periods of time.
@@SchrodingersBox Yeah.. I wrote when the video very first started... Nice fix btw. I watched both videos.
Surging idle usually means it's not compensating for the lean/rich cycle the engine does to prolong the life of the catalytic convetor. Typically caused by a bad MAP sensor.
Also explains the hestitation of the engine during accel, because that's what these Honda's predominantly use during WOT, as it goes into open loop.
Not saying 100% this is the case, but it'd be what I'd look at first.
But that'd just be me projecting, because I already regularly send my Acoord in for valve lash adjustment :D So it couldn't be that.
And yeah, I had to really press my mechanic for the adjustment, because he didn't believe a modern car needed it xD
Check exhaust back pressure at 2500 rpm. Oxygen sensor 1 bung is a good place to check the pressure.
Bill G
With restrictions in fuel trims, that's an indication of lower combustible air volume, right? As to why the reduction in fuel?
Yes, I believe the rich condition is due to improper “breathing”- particularly , exhaust leaving early.
The car nobody could fix finally fixed by somebody.
Awesome!!! Cant wait to see part 3! i mean 2
Did you check the temperature it will run rich if it still cold. Then if it gets warm it will run lean.. Maybe you sgould chexk the temp and thermostat
Hate to advise you it sounds like what my toy 4 runner did. Changed the exhaust system muffler not thec. Catilytic converter. Definitely didnt run as rich cut my emissions in half finally ran well the taken.
It needed it anyway.lol
Very interesting. I can see your thought process and looking forward to what part 2 reveals
Thank you! great to see you back!!
When I was at honda, "valve adjustment misfires" showed themselves when the engine was cold but went away when warm
I ran into the same problem .it ended up being a charge air temp sensor in the air filter box. Now to add a little more to this . The map sensor also can read air temp along with barometric pressure but the sensor I'm referring to is in the air box it's self .. I've seen problems with the plug and wires being broke from air filter being changed.. persons changing the filter sometime tend to be rough when trying to remove the filter.
interesting. seeing as how an IAT contributes maybe 1% to STFT it seems impossible you would have a drivability problem from it. what was the voltage you saw from the IAT
My dad had a 98 jeep grand cherokee laredo with the 5.9L V8 ...
It cranked and ran for 5 seconds then shut off.
It would crank and crank but no fire.
Had no spark, replaced the coil, still no spark
Replaced the crankshaft sensor and camshaft sensor, still no spark.
Replaced the distributor, still nothing.
The coil was not getting its signal.
Replaced the ECU, fired over for 5 seconds and shut off again and would not fire over again but cranked and cranked.
Got the ECU swapped again, fired over again and ran for 5 seconds then shut off again and would not fire over. Just crank crank crank.
3 mechanics could not find out why it would only run for 5 seconds ...
We had to sell the car as is. The guy who purchased it ran into the same issue and could not figure it out, he junked the car.
I would have loved to tackle that one!!
Timing chain may have been the original issue. Timing may be off now due to not relearning cam/crank correlation after replacement.
Very good guess!!! Not quite the issue but close!!!
I installed a used engine in an Explorer I owned a few years back. I never relearned cam/crank correlation. Thing ran perfectly, BUT it would set the CEL and flash it at WOT on the freeway. After much diagnosis, a relearn of the cam/crank correlation fixed it.
That Honda runs a belt. ITs effecting both cylinders (both fuel trim is negative), so if there was an issue with timing, I would think its with the crank. Maybe crank gear is worn at the key? Cam/crank correlation would rule that out. Or Maybe Matt can see something on the in pressure probe (I am still 1/2 way through this video).
The oil is it black does it indicate any metal in the oil pan. These things are known to have camshaft lob ware problems
When you reved it the first time I heard knocking/tapping and was thinking valves and then you started mentioning them and did a compression test and I had to make this comment before you do anything on the valves or even see them
It had no engine noise and in retrospect we know why.
Surprised dealer didn't suggest valve adjustments as that is something is missed lot until eventually usually will trigger random misfire or rich code. This very common on all v6 3.5 2003-2015
What about a 97 f150 4.6 4wd,?, Mine does the same as the Honda. Except mine will eventually start after it backfires 1 time through the throttle body, rough , violent idle, no throttle under a load, I've replaced everything they replaced, still no change
I have a 2010 I changed the engine immobilizer on a Toyota Camry 6cyl 3.5 and now it starts but it sounds like a vacuum leak
Okay so I know this seems stupid but also take a look at the power steering pressure sensor and connector/wires. Issues here would cause drivability issues.
Hmmm never heard of that- how would that cause these issues exactly?
A 4 CH Scope would be of great help here. And fuel gas angelize test. After hearing what all has been replaced and listing to the vehicle, I would have to narrow it down two things. Do we have stoki in the cylinder's? 14.7 to 1. Is there valve timing issues here. I'm thinking mechanical here.
Only watched a few minutes in so far but with high miles Honda the valve clearance is always a suspect due to valve seat recession.
I was about to say the same thing about valve adjustment. When I used to work for honda we saw a lot of driveability issues but with valves being too tight. I believe there is even a maintenance schedule for valve adjustments on most Hondas.
I've seen twisted cams and and a broken pen on the cam sprocket allowing the cam to shift ever so slightly causing a rich condition.
I considered that too!!
Ivan just ran a video on that the other day.
Both banks are effected with this Honda. I would look at the crank alignment.
Why didn't the main dealer check the service intervals? Tappet adjustment would have clearly been shown after reaching a certain millage,200,000 miles without adjusting tappets is crazy,A great diagnosis but when I work on my Pickup or one of my bikes I always carry out Maintainance according to service interval,
Hi Matt, great case study mate👌
OK. I am 7 minutes in the video and I am already asking myself if any one of those shops checked the valve clearances. The honda engines are well known for needing these adjusted atleast every 100k to ensure they are in spec.
19:34
Low compression would cause the MAF to read less air suction which would cause the ecu to dump less fuel, less fuel would cause a lean condition.
Think about it, you have say 4 cylinders, if all 4 were in good compression they would inhale say 400 cfm and the maf would relate that 400 cfm to the ecu and the ecu would release enough fuel for 400 cfm and it would run normal.
If 1 cylinder was LOW on compression, it would not inhale 100 cfm, but maybe 50 or less. So instead of the motor inhaling 400 cfm which would be the normal, its only inhaling 325 or 350 cfm so the maf will tell the ecu that its breating 325 or 350 cfm and the ecu will release enough fuel to support 325 or 350 cfm which is NOT enough when its normally 400 cfm which will cause a LEAN condition .... now you got 4 pistons that are used to 400 cfm worth of fuel and now they are only getting 325 or 350 cfm worth of fuel ... less fuel = lean condition ...
You cant test the vtec while its idling because the system requires more oil pressure to be present than at just idle. The vehicle won't allow it or else you could cause damage to the motor when the vtec solenoid allows oil to run into the head and lock the rockers onto the high speed cam profile.
yeah on my autoenginuity it states to bring engine to 2000 RPM for that reason. and even then I have done it at idle. but the Autel didn’t even give me the chance to do engine running.
YES HE'S BACK!!!!!!!!
Lol I never left!
Sir, you do mean that it's running LEAN because it has that minus character which means that it aint getting enough fuel, try adding fuel cleaner or change the air filter.
What does the valves clearance looks like? Honda vehicle likes valves clearance to be on the max side, tight valves will cause fuel rich run rich condition
I've seen late valve timing caused by a shear pin failure cause these symptoms.
Without watching yet - 3 culprits likely/possible - non OEM MAF.. non OEM Lambda sensor, V-tec not adjusted/starved for oil. With no lights lit - it's the Vtec more than likely. Maf/Lambda would probably light the light. That's after the boggo servicing/check exhaust etc etc is done. First up - go through the Vtec. Chances are it's not getting activated/enough oil/is out of sequence blah blah. Wouldn't even fire up the scanner for this one - poke the cams.
Look at map voltage. Over 1 volt hot idle you need valve adjustment.
why is that not due to a intake leak or VVT incorrect setting? Why does MAP over 1 indicate valve adjustment specifically?
@@SchrodingersBox It's normally at .85 Just a quick check. Most Honda guys know this. Bad idle, stalling, check map voltage.
Just a data point. 2001 Jeep Grand Cherokee. Surging idle, but usually runs well. Look like the computer was seeing variable load (commanded ignition timing was all over the place. Finally, it stalled and I got the data from the computer. Seems the MAP sensor went from good vacuum to zero vacuum instantly. Turns out the MAP sensor itself was faulty - every now and then indexing to atmosphere.
So... Look at the data streams. 12.9% load at idle?
As for cam timing - yes compression test, but also vacuum. The scan tool said the absolute intake manifold was at 3.x psi and your barometer was at 11 (Are you in Colorado? - shouldn't it be more like 14....) so that is 8 psi vacuum (about 16 in Hg) That's a little on the light side for most passenger side cars.
Hail Mary - put a smoke machine on it and look for a vacuum leak.
The weird thing with computer control, just because it's not idling lean, doesn't mean its not a vacuum leak of sorts. The computer adjusts....
What would be really cool is to find another Honda, similar engine, and see where the sensors should be reading.
As for your in cylinder pressure. That is a slippery slope. You can spend years on cam timing esp cam timing at idle. But if the exhaust valve timing is 250 degrees advertised, that means it has 70 degrees more than 1/2 turn. Split that and your looking at 35 degree advance.
As for valve opening vs. air actually flowing. Most cam guys tell you NOT to look at advertised degrees - just because the valve is open .001 doesn't mean air is actually flowing...
If you really want to see what is going on, they have laser drilled spark plugs that have piezio sensor directly in the combustion chamber.
No idea what may be going on But I feel like you are using a scientific way by using Cunningham's Law. 😂 Love your videos.
Not really familiar with that model but from all the symptoms you described the variable valve timing isn't working..
Nice job. I also have a strange prob with a check engine light on a 2003 maxima with 58k miles which I'd like to find.
Just listening to idle definitely not cam lobe wear. Just by ear and years of working with Honda engines they tend to develop a very noticeable TICK with worn lobes
Love valve adjustments!!
No, seriously!! I'm weird that way.
LOL, there are 2024 Hondas that still need valve adjustments as part of regular maintenance.
Same problems to my Nissan Murano...and change the alternator. Problem Solved.
and what was your diagnosis with the alternator?
@@SchrodingersBox not charging enough... causes protect any electrical transmission parts(I punch gas and won't run).
SUBSTANTIAL Schrodingers Box
Thank you very much for sharing with us great tutorial God bless you and all your family around you Schrodingers Box
From Nick Ayivor from London England UK 🇬🇧
Bad injectors?
would have been nice to see the pulse testing on the intake and exhaust
Use the scope if your tool has it.
Would a fuse on a immobilizer system cause it to run like a vacuum leak?
No. It would cause a no start.
2000 c3500 iac keeps idle high during drive.. only comes down when car stops
Pretty simple fix. First is it a speed density design or not? If it’s speed density design then the fuel trim will show the issue.
I would datalog it and see if you are getting ignition advance when you are supposed to. My guess, a bad knock sensor mistakenly pulling timing causing it to run like dog poop. Also, I don't think that fault would trigger an engine code. Can you see ignition advance against rpm and engine load. If it was pulling timing as you rev up, it would also go rich, maybe? Het, also, when doing the compression test, make sure the throttle is WOT. Also, you can do a leak down test to tell you if the valve adjustment is so bad, that it is leaking pressure. Final random thought : Is the rubber on the harmonic dampener torn causing sensor signals to be retarded compared to what is actually happening? I would use a degree wheel and a screw in stop to confirm indicated is the same actual TDC.
The ending of this video clearly shows how master technicians like myself are getting slaughtered financially. Generally we are only paid an hour to figure ALL of this out.. and generally speaking shops don't have Pico or anything with transducers. Worst of all, even when you have concrete evidence of a valve timing issue.. you have to offer to eat the cost if it doesn't fix everything. I should have gone to engineering school and do this as a hobby too. There is no payoff in the auto industry for being this smart.. which is why the parts cannon is prevalent (not in my stall).
i appreciate the honest insight. Yes I have always tried to make it clear that I have a huge, huge advantage over a tech in that I can take much more time to diagnose things than they typically can. no doubt- I would probably be doing some educated guesses if I was in your situation!!
thanks again- I always appreciate comments from the pros.
Would a vacuum guage help you to pinpoint the issue?
how would that help?
having a oscilloscope is money well spent for diagnostics . a multi meter and clamp will get you into the rabbit hole and oscilloscope will get you out
Great perspective!!! I agree!!
The problem is the manufacturer gave the Odyssey a reputation for not being a quality vehicle sadly enough , certain years are worse than other years
How to find rich or lean condition in petrol cars?? Thanks.
I'm thinking of a new business model.
I'm going to start dumpster diving for parts....so many parts changers I could make a lot of money selling perfectly good parts that were thrown away.
Hahaha. so actually I do employ that to a degree already. very very often people come to me and they already bought the part they want me to change but when I find they didn’t need it, they often just leave it with me because it’s non-returnable. Then I can charge for it if I do run into someone later who needs it.
@@SchrodingersBox haha perfect!
Cylinder leak down test? Fault in valve sealing.
very good thought but look at the compression- no leak at TDC.
at 15:15, it seems like you're mixing up VTEC/VCM with VVT. I'm not an expert, but my understanding is that even a VTEC system used for variable valve timing would not affect CMP signal, because it isn't phase shifting the cam, but instead affecting the rocker arms. However in this vehicle, IIUC, there isn't such a thing, but instead VTEC is only used for cylinder (de-)activation (VCM), and that seems to be what that test is for. VVT tests are probably hiding somewhere else.
No. VTEC only changes valve lift. i-VTEC has a phaseshift on the VTC gear where it can adjust the timing, next to the valve-lift from VTEC.
Time to check exhaust back pressure. ----2kpa, +6kpa, intake, exhaust respectivley.
Based on what evidence though? what evidence are you seeing that backpressure is the issue? looking at the MAP voltage how can a clogged exhaust be the issue?
Is it a press fit cam? I.e. are lobes press fit onto the shaft?
Not on this model, no
We bought a brand new bmw m1 convertible back in 2014 it had a similar fault to this out the dealers and I’ll give bmw there dew they tried and tried to fix it but in the end they actually took it back gave us another one because they couldn’t fix it either lol
Interesting vid enjoyed it 👍
That’s hilarious… but kinda sad too lol. glad they made it right though!
Not as glad as me 🤣 I was bricking it thinking they’d flogged me lemon but they were great . I believe because they couldn’t fix it it may have gone back to bmw HQ to be looked at or so the sales guys said to be analysed in case it became a problem on other cars I guess anyway no harm done , wish I’d bought something else it was a pretty car and nippy but it was like driving a go kart with no suspension horrible thing didn’t last to long 🤣 cheers my good man 👍
(VTEC) solenoid has a oil screen in it that likes to get clogged.... WatchWesWork does a good video on this problem
The VVT data indicates this cannot be the issue though.
Do you know that Honda use mechanical lifters
I know now! I didn’t until this video
I have a 2008 dodge caliber srt 4 that giving me code p0171 I have changed spark plugs ignition coils and oxygen sensor , and maf sensor and it still not running good do you think you can help me ???
What data showed this was an ignition AND induction problem? That seems really unusual.
Never seen low compression on an engine cause that aggressive rich mixture on efi before
I don’t think it’s low compression as much as where the compression is leaking.
What's the MAF designed for a different size engine?
Yes- I believe later model years used this design.
A spider supposed to have 6 eyes. Maybe he was looking into the problem ?
Oh my god lol. smh!!
Did Some wiz-nat Mec-in-nic, change the first Timing Belt and get it timed Wrong, way back when?
Wouldn't you Check Timing belt Marks First? Before tearing into Valve Adjustment?
I did originally. timing was correct. i actually did it by synching ignition input signal to compression though rather than check belt. timing was correct either way.
@@SchrodingersBox Very cool,and I learnt something..Thanks for making the videos..
I can't help only to say CPU firmware could be issue
how so? what evidence is indicating that?
Is it broken pin in cam?
No we know it isn’t because the cam and crank sensor correlation is correct.
Good thought though!!!
The more mysterious the cause, the simpler the solution.
Please fix my 5.7 hemi then….rich running…but happy’ish after 1500 revs?.?
What’s “happi’ish” mean? Sounds like the clue is there.
I noticed that the air intake temp was 111 degrees and I don't see you sweeting.
Hahaha. remember the IAT is in engine bay with a warm engine so it’s much much warmer than ambient. ambient was about 80F
I bet Exhaust valves are too tight, adjust the tappets, they are manual not hydraulic.