How To Check Valve Timing Without Dismantling Engine

[@2491kridge]

Easily the best layman’s explanation of this tool that I have seen

[@lanwickum]

Around 2006 I was rebuilding transmissions for a CAT dealer. Started to use pressure transducers and logging the pressures for shifts and such. Learned so much more about what I thought I knew when I could start seeing clutch fill times, dump times, valves opening closing. It was then that I could confidently explain what every orifice and valve did. Had an older tech that worked with CAT engineers years before this. They graphed pressures with needle and paper graphs. He had a chance to already see and know this stuff. Helped make him a very good tech. Wonderful knowledge to learn when we see what is really going on. That and we had excellent data to know what was going on when we shipped it out. Could see the change, if any, next time we rebuilt the transmission. CAT mine equipment build the hours quick. Runs 24 hours a day if possible.

[@tjfgermany58123]

Hey Matt. Watch same videos multiply times. When i see a video that is 10 years old I relate it to seeing the light from a star that is actually billions of light years old. And I think I am way behind the learning curve. Good thing I can watch a video faster than it was made. Thanks

[@SchrodingersBox]

Hahaha good analogy. In fact many of the stars you see actually no longer exist. They burned out millenia ago but the light is still approaching.

[@jacksonmusyoka1216]

I like the way you teach you've made me be so passionate about automotive repair, waiting each day to apply what I learn from your channel.

[@SchrodingersBox]

Great to hear!

[@John76546-x]

Matt, oscilloscopes are available for under $400 for handheld 2 channel and are good scopes from 60 to 100 MHz. Not the deep memory the picoscope has, but very useable. A Hantek 8 channel scope does perform fairly well and costs around $100. A pressure transducer that works from a 9V battery can be built for under $60, not including the compression tester kit which is on Amazon and Harbor Freight for under $70. I did a video years ago on how to build one and have made several small cased self-powered units since. Many mechanics probably already own a compression tester.

[@calholli]

There's a $5 "diy oscilloscope kit" on ebay. I've watched a few videos of people testing it, and it seems pretty cool for being so cheap. (it's the red circuit board)

[@iam1smiley1]

Is the Hantek 8 scope any good? Amazon comments section generally said their amp clamps weren't great though.

[@John76546-x]

@@iam1smiley1 If you want a first scope and to learn on and do some testing with, yes it is. There are some reviews that show how it works and its limitations on KZbin. Also, the Autel Maxiscope works quite well. You can download software like the Picoscope online and try the software for free. The Maxiscope is around $350 on Amazon and I found one on Offerup for $249. Picoscope also makes an inexpensive 2 channel scope for like $150 that does not use automotive software, but Picoscope 6 software is very similar you just have to make all settings.

[@richardcranium5839]

@@calholli its better than nothing but its sample rate and bandwidth make it tough to consistantly get clean waveforms

[@juansolo1617]

@@iam1smiley1 The Hantek scope is actually nice for the price, but the software sucks. There are alternatives, but they're not too great, either. Very much improved over the factory software, though.

[@rickrogers2649]

I've seen the pressure transducer used in videos but thank for helping us mere mortals to better understand how to interpret all this info. Thanks for remembering that many of us don't have all the equipment that the pros need. Great video. much appreciated.👍👍

[@SchrodingersBox]

You're very welcome! I appreciate your perspective, it’s what I am aiming for. even if you don’t have the equipment- it is helpful to understand the mechanics of this stuff so maybe you Can come up with your own methods

[@jaguarblack4332]

Facts

[@jaguarblack4332]

@@SchrodingersBox I really enjoyed this information.

[@Tony-rl2fr]

Great video as usual. Love your enthusiasm and presentation. I'm looking forward to more scope related diagnostics even though, as you mentioned, it gets pricey $$. Still interesting and there's always something new to learn. Thanks Matt 👍🏻🇺🇲🇨🇦 🇦🇺🇺🇦

[@SchrodingersBox]

More to come! Thanks for the comment!!

[@TheFuneralDirector]

Jeeze you have broke the bank with this one ... those Haynes model engines are 40 quid here in the UK .. thank you for you knowledge by the way, take care regards Andy

[@bartscave]

Excellent video! Good explanation of the scope pattern

[@SchrodingersBox]

Thanks! 👍

[@Lambros_Stefaneas]

Thanks Matt,for this great video. Keep posting (teaching)more hi tech tools video. It's time, to move in to the next level,all of us,including the DIY 's😂.Drag them in ....

[@rich13la1]

Really enjoyed your presentation , do not own that fancy equipment but the knowledge you shared can still be used in diagnosing .

[@SchrodingersBox]

Glad it was helpful! i totally remember just skipping over any videos where someone used a scope or anything “fancy” and it was a huge mistake. you actually really learn the concepts better with this type of equipment. i used to think you had to master this stuff for this equipment to be useful. it’s actually the opposite: this equipment is useful if you want to master this stuff.

[@bobbrown3317]

an understandable explanation of a pressure transducer waveform, thank you

[@nickayivor8432]

SUBSTANTIAL Schrodingers Box Very helpful video tips thank you👍Take care Schrodingers Box From Nick Ayivor from London England UK 🇬🇧

[@SchrodingersBox]

love my viewers from across the pond!!

[@nickayivor8432]

I love when you used Oscilloscope PicoScope, also voltage drop testing on vehicles thanks again God bless you Schrodingers Box From Nick Ayivor from London England UK 🇬🇧

[@stuckinmygarage6220]

THAT was def fun, Professor Matt! So cool to "see" dynamically, eh? 😎 Love yr excitement, always. Don't forget to "Spring Forward" 😉👍

[@SchrodingersBox]

it was fun!!! i had a blast doing this one!!

[@nukesploder]

So this is a great video, and now that I've watched it I have a couple of thoughts. I would love to know what the monitor shows on the problem car now that you've showed us what a good, running engine looks like. I wonder if there's an issue with the camshaft or lifters not properly opening such that there occurs here a rich condition. it could be that it IS a timing issue, but not on the exhaust or intake stroke, but perhaps even a faulty or clogged fuel injector. I don't know. Either way, you've probably diagnosed my thoughts a billion times over being the knowledgeable person you are, but that's just some thoughts I've acquired upon consuming your fantastic vid. Thanks for the great content and the video! I learned a lot about what a running engine looks like. I had no idea that the opening of an exhaust valve during an exhaust stroke would occur so early during the stroke reversing the negative pressure. Observation: that timing, during 100-150 on 16:20, where there is a slight interval in the peaks and troughs, is that where that 'famous v8 rumbling' comes from? That would seem to be a logical conclusion for me based off the graph! I've heard it's from a time interval between a time frame of the exhaust and intake valve opening and closing at roughly the same time. Something interesting to ponder! Anyways, thanks again. Appreciate your time and video tremendously!

[@georgerocks5191]

Great video. Many techs produce videos on how to fix a car but you do that and add the theory behind the fix and how to get there. Natural teacher. Regarding this repair, would a running compression test help in identifying the issue since It provides an idea of how the engine is breathing?

[@SchrodingersBox]

Thanks for the comment. while it certainly isn’t definitive, I do sometime use compression to give further evidence of a timing issue. an out of time engine usually needs more strokes than normal to max out the compression gauge so if I notice this pattern on a compression test it further evidences out of time. it’s especially useful if only one bank is out of time since the other bank can be a negative control.

[@georgerocks5191]

@@SchrodingersBox Thanks- maybe you misunderstood my comment. I mean to do a compression test with the engine running. This is a good way to check how the engine is breathing and an indirect way for checking valve timing. Perhaps Im wrong...

[@SchrodingersBox]

oh I thought I did that in this video- maybe it was another one. yes- I have a video where I do this. the best way is with a pressure transducer because you can measure the actual degrees of valve opening and see in real time where it is opening relative to the compression stroke and clearly see if timing is off.

[@shaunoconnell312]

Good video, Eric O South Main Auto explains this really well also Ivan at pine hollow. I don't quite understand how a tight valve can cause a rich mixture.

[@SchrodingersBox]

it’s because you are releasing the exhaust early which diluted to oxygen content. less O2=rich.

[@simonparkinson1053]

20:05 the small glitches on the trace during compression and exhaust strokes are interference created by the ignition events, effectively giving you an extra scope channel for free!

[@foxy1960]

Well spotted

[@calholli]

It would be cool to see you try the $5 to $20 "diy oscilloscope kit" on ebay. It has a red circuit board and looks pretty cool for basically being free.. It's only $5 for the kit, and you solder it yourself. Or you can pay a little more for them to be pre-built. Please look it up; I think it would make a great video for you to thoroughly test it.

[@scientist100]

Not worth it. I started with the 1008c and never used it because the software is not friendly and time is money in this field so you lose more with frustration and inaccurate or incomplete data.

[@pl5882]

Have one. I haven’t tried it with a pressure transducer. The unit is more novelty than anything but I think I did use it with a pulse sensor and was able to diagnose a leaking exh valve. Definitely better than nothing.

[@calholli]

@@scientist100 It only costs $5.. If you used it once to solve a problem, it already paid for itself.

[@calholli]

So where do you buy that transducer? I seen Ivan at Pine Hollow using one a few times also. He put one on a front side O2 sensor port/ hole, to check if a catalytic converter is clogged; It definitely was.

[@SchrodingersBox]

Oh I am sure this is something Ivan would use. i bought it right from PicoScope. You could certainly use this for exhaust backpressure. i have several videos using a vacuum gauge for that but this would work too. Not sure I want 500 degree exhaust gas in my transducer though lol.

[@michaelsparmann3368]

@@SchrodingersBox note that Ivan sells a lower-cost option for a Pico-compatible pressure transducer, perhaps you might want to ask him if he could send you one to try out and compare to the "official" Pico one?

[@Lambros_Stefaneas]

@@michaelsparmann3368 The quality of the waveform and all the specs,can not compare with pico transducer, unfortunately. We have to pay for good(top) quality... It's like a foto, to have a clear and good quality foto, you have to buy a good camera. And also, pines transducer, cannot reach 500 psi,is much less the limit. I am not saying it's bad ,but I don't think can compare with pico 's one.

[@michaelsparmann3368]

I guess it depends on what you need. I have zero experience in automotive repair, just watching this for entertainment. But I think what you say makes it even more worth comparing, to see if it is good enough for most automotive repair applications. You don't always need that highend camera if you just want to check e.g. the physical location of something. A transducer costing more than a scope just seems like it might be a bit overkill for the task at hand ;)

[@Pablo_Automotive]

Nice explanation Matt it's always great watch your videos

[@elbertmarks5799]

Matt - Neato - QUESTION, Can the transducer be used as easily on an OBD-1 car as well as on the OBD-2 cars? My 1993 Protege 1.8L SOHC MTX had a no-start which a local shop fixed by installing a new distributor. BUT it now only gets 24 mpg ( got 35 mpg for its previous 330,000 miles) and now starts like new with engine cold but (disconnecting one of the injectors is now required to start when engine is hot). Seems like it might be a timing problem. BTW, I get no diagnostic codes.

[@SchrodingersBox]

Yes a transducer has nothing to do with OBD. it is 100% a mechanical feedback.

[@elbertmarks5799]

@@SchrodingersBox Thanks Matt.

[@nokalamaduna2709]

Wow, Sir Matt, that was awesome and I have only one word to describe that experience, FANTASTIC. I will assume that this variable valve timing technology will occur under certain conditions like engine speeds and loads, maybe that is why it runs rough at idle, just my 2 cents Matt.

[@SchrodingersBox]

Exactly. i will cover. VVT soon

[@nokalamaduna2709]

@@SchrodingersBox Looking forward to that video Siir Matt.

[@CharlesCharles575]

thank you Sir l really like your clear and easy explanation

[@jodyip1364]

Can you bend valves just by swinging of the timing is of and the belt on because I recently changed the water pump on polo 9n 2006 think the timing went of or so

[@SchrodingersBox]

You can definitely bend valves if the timing is off.

[@jodyip1364]

Thanks is a polo blm 8v or 16v 2006

[@ablackformula]

You can load the sample tests like you did, and then press the play / record button. Now you're using the same settings pico used for their sample test, to run your own test. Also, on the expansion stroke, the piston is moving downwards, creating a vacuum in the cylinder, when the exhaust valve opens. You then reach atmospheric pressure in the cylinder, while the piston is still moving downwards. I feel this can only be explained by exhaust manifold pressure (atmosphere) entering INTO the cylinder. That is interesting! Exhaust gas enters the cylinder, then gets pushed out as the cylinder travels back upwards during the exhaust stroke. This is probably not true for a firing cylinder though. I'd imagine the combustion pressure is still high (above atmosphere) in the cylinder throughout the entire downward travel. In this instance, exhaust flow would be out of the cylinder the moment the valve opens. I look forward to a spark plug/transducer combo where we can monitor cylinder pressures during a firing cylinder. Perhaps on a dual plug hemi if anyone's willing to risk their transducer lol..

[@richardcranium5839]

on vvt engines disable the vvt to get a baseline, since even at idle some computers are constantly adjusting the valve timing. not withstanding you could have a bad vvt phaser anyways. this is a good way to check that the vvt is diong what a scan tool is telling you as a double check.also with vvt disabled a simple cam v crank signal check should tell if its in time. its a learning curve for sure

[@jaguarblack4332]

Needed this information. Thank you

[@SchrodingersBox]

Glad it was helpful!

[@RooneyRony]

Hello, i need some help please i have a 2014 2.0 ford focus about 76k miles . It had around 3% on STFT and -7% LTFT . Now ive changed the spark plugs cleaned the MAF and throttle and its from 5 to -4 % STFT and around -11.5% LTFT. Need some advice where to look forward ,whats wrong

[@SchrodingersBox]

i don’t understand what’s wrong- what is the issue? those numbers look normal.

[@RooneyRony]

The rich condition just goes up in such a short period of time, yesterday it was 0 on the short and -11,5 on the long .

[@SchrodingersBox]

what rich condition?

[@RooneyRony]

The negative long fuel trim, am i wrong?

[@SchrodingersBox]

i don’t see anything wrong. what symptoms do you have? do you have a P0172 or P0174? i don’t see how that would be possible.

[@ZoomAutoDiag]

I see you liked Brandon Stecklers syringe demonstration. He is the man for pressure waveform analysis. 👍🏻💪🏻

[@SchrodingersBox]

no idea who that is. will have to look that up! anyone who uses a syringe for an engine demonstration is Ok with me lol!!

[@ZoomAutoDiag]

@@SchrodingersBox oh wow. You should check his book out on aeswave pressure waveform acquisition and analysis from the inside out. He is a big name in the automotive training world. Unless you are being facetious... Lol I don't see you doing that so I will believe you don't know who he is but awesome fella.

[@SchrodingersBox]

Hahaha no I honestly never hear of him- I don’t really watch any other automotive videos other than scannerdanner. he’s the only one I really watch. but I will check this guy out right now- sounds very informative.

[@SchrodingersBox]

well I must say I found a video of his that you must be referring to (yep- he used a 50CC syringe in a pressure/vacuum example lol!!) and I can tell you after just a few minutes I am intrigued and will surely watch the whole 3 hour session. Good call- he has excellent presentation. Really excellent. Thanks!! i look forward to this new resource!! But I do have to say- I don’t think I would be able to understand what he is saying unless I already had a fairly strong foundation on concepts of pressure, vacuum, and electrical. He’s a bit advanced.

[@ZoomAutoDiag]

@@SchrodingersBox yes he is. But there are numerous resources and Bernie from ATS does some great explanations of pressure transducer . I think Brandon does some explanations of the absolute and even the pressure pulse sensors used in vacuum and pressure acquisition.

[@therealspixycat]

Unrelated question: how does the ecu detect a misfire?

[@SchrodingersBox]

That’s a great question! it does it using the crankshaft position sensor. when it detects a slower revolution in the crankshaft after an ignition event, it determines that must have been due to misfire not pushing piston on power stroke so it ties a misfire code to the cylinder that just fired. also it can determine an electrical problem on a coil or injector such as an open circuit- but if coil and injector both operated and crankshaft movement was slower it detects it as described through the CKPS.

[@topezful]

Great Video as usual

[@SchrodingersBox]

Hey hey good to see you back!!!

[@reginaldbchellew5482]

Fantastic technology congratulations ......

[@int53185]

Particularly useful on engines such as this where you have to pull the engine in order to check cam/crank timing marks. The parts canon would overheat before that was done!

[@caminobean6248]

Hello Matt, your videos have helped me immensely! But you got me wondering about the ripple in the exhaust pressure after BDC - instead of, or in addition to turbulence, could the transducer be seeing teeny weenie pressure pulses in exhaust pressure in the exhaust manifold from each of the other 7 cylinders (when they are exhausting)? If that is the case, could you use that to diagnose a plugged or partially plugged cat? If one cat is plugged, then those teeny weenie pulses might have greater amplitude that the other non-plugged cat pulses, showing perhaps a two level amplitude pulse. SEE? You got me to THINKING! By golly, it looks like there indeed is seven little humps in that thing.

[@SchrodingersBox]

You very well may be right actually. others have also mentioned it is more due to turbulence from other cylinders’ exhaust in the manifold. I guess a way to know would be to look at a cylinder with an exhaust valve issue vs one without. great point though.

[@curtgirardin6093]

@@SchrodingersBox Just keep in mind, the other cylinders aren't all exhausting at that same moment. It may take a little time for the pressure pulses to move throughout the exhaust system though. I, personally, would chalk it up to turbulence (mostly). But I think you could definitely use the exhaust stroke part of the waveform to find exhaust restrictions. Just my 2c. :)

[@AGuysGarage]

If it turns out to be something other tha n the timing, do you think you could set up a pwm style injector tester? the reason i am asking is thus: say all the injectors are working correctly but one and it has an issue where it is flowing too much the computer starts pulling fuel because it is pig rich, then it starts missing and such because all of the other cylinders on that bank are lean because of the one injector. Just a thought, i am probably not even in the ball park because honestly i caught the first part of the video when the symptoms were described and fell asleep until right there at the end. "oh i saw the engine cut out too" was no fault of yours, i love your videos man. you are one of the best diag channels out there. i was just bushed from a long week and i am not really a spring chicken anymore ;P. " i will rewatch it later" just wanted to ask that question straight away. ya my punctuation is trash today, as well as my grammar so take it easy on me on that front please. early am and probably headed back to sleep here in a bit.

[@SchrodingersBox]

Hey good to see you back- Rhage- against the machine lol. Your case scenario is totally valid. Yes you would see a rich condition response on one bank but because pwm of the injectors is by bank instead of by injector, you would lean out the other injectors causing random misfires on that bank. There are a couple ways I might address this. In the old days I would use a pulse injector tester like you mentioned- I would have a fuel pressure gauge attached and prime the fuel system and pulse each injector until I found the one that is leaking. but this assumes I would know there is a leaking injector problem- discovering that would be pretty intensive. But nowadays I would probably do it differently. i would use a capacitive pickup to get ignition waveforms. i would be able to see the low fuel waveforms under load on all but one cylinder on a bank clueing me in to that exact cylinder.Basically, one cylinder is going to be different on the waveform so I immediately know where to focus. . based on waveform pattern, I would know it’s either fuel or ignition on that cylinder and once I validated ignition was good, I would know to go towards fuel injector for that cylinder again with the pulse tester but I would only have to test it against one known good since I would not have to try to find the bad cylinder . This would be way faster than I would have done even 3 years ago. and even now-- I understand the newest vehicles not only have individual injector control, but also can be controlled with a scantool. if I adjust PWM on each injector and one causes a different response than the others, I could identify a bad injector without even opening the hood! but again- we’re assuming we know to go to the injectors first- normally we don’t know that.

[@AGuysGarage]

Rock on bud, I knew you had it covered

[@speedy_pit_stop]

That was awesome. Thanks for sharing.

[@thesetruths1404]

If I'm calling around asking for a complete timing check, 6 months after I paid to have the timing kit done, what is the best things to ask for? I have a boxer 1.8L Subaru motor that has dry 76/78 psi compression on #2 and #4 cylinders. The first shop i paid $120 for just a trst drive and dry compression test. What a joke. I don't have any fluid or oil loss or cross contamination, or overheating. I simply have poor power uphill and speeds over 60 mph. Thanks.

[@SchrodingersBox]

$120 is actually a bargain these days to be honest. If you have a check engine light on with any kind of cam/crank correlation code then I would take the car to the shop that did the timing kit, as they must have mistimed the engine during the install If however there is no check engine light on, it’s highly unlikely you have a timing problem. You will need to get a diagnostic done which is usually $150/hr or some places even charge a minimum $200. Remember this may not even be an engine issue. It could be you have a frozen brake caliper, driveline issue, transmission issue or otherwise.

[@thesetruths1404]

@SchrodingersBox it's a compression issue. #2 #4 only have 76/78 psi dry compression.

[@SchrodingersBox]

Yeah that’s a problem. at very best it’s timing on one side of the engine (i think 2 and 4 are on same cylinder head if i remember correctly) and at worst it’s a gasket leak between the two. in any case, a substantial repair for sure.

[@thesetruths1404]

@SchrodingersBox yes 2/4 are on driver's side. Can't a fair shop do a compression, leak down (on that one head), and coolant gas check in an hour? It's a non-interference block so it could be a leaky valve, but not sure how timing cam could allow air to escape on 2 different cylinders adjacent to each other when one is being tested. Is that even possible in a SOHC head?

[@SchrodingersBox]

I can’t really say what a shop would do or charge since I am not from the industry- I’m a DIY. I personally would do a relative compression test and overlay with ignition timing. Or better yet- a cylinder pressure transducer test overlayed with ignition timing. Either would take about 10 minutes and would definitely answer if this is a cylinder leakage issue or a timing issue. I’d do it for free of course, if you lived near Denver. But I don’t think a $200 charge by a shop is unreasonable based on today’s typical pricing for diagnostics.

[@javiTests]

11:34 The explanation is pretty cool with the semi-destroyed engine 😂, but I think we're mixing concepts here. The explanation says that after the explosion occurs, when the piston is at the bottom, there is going to be a little bit of vacuum. I don't think that's the case in a proper running engine (maybe in those with Atkinson cycle, I don't know). It appears like that if we use the pressure transducer because that cylinder is not running, right? If I'm not mistaken the pressure transducer replaces the spark plug so there is no ignition. If the engine was running, there should be positive pressure in the cylinder before the exhaust valve opens. Edit: Ah, right, later at around 28:00 there is an explanation of what I said, but yes, I think in a proper running engine the only vacuum would occur in the intake stroke if the engine doesn't have a turbo or anything.

[@SchrodingersBox]

yes agreed the waveform would be different if there was an actual power stroke. but given there is no power stroke with the transducer, there is definitely vacuum before BDC in this example. i guess there is no way to catch a waveform on an actual power stroke - without drilling a hole in the cylinder lol.

[@paulpaquette1961]

@@SchrodingersBox You can on a 2 spark plug Chrysler Hemi. Try it when you get a chance! You'll be impressed with the shape of the waveform. When you were testing this vehicle, while the transducer is installed, if you would have walked back to the tailpipe with a dollar bill, it would suck it in when that cylinder went south on the power stroke. That's the o'l dollar bill test to see if there is a misfire. The moment the exhaust valve opens the vacuum across the face of the piston (due to lack of combustion occurring) would "suck" the bill into the tailpipe during the cylinders equalization to exhaust stream pressures. Happy Transducering!!!!

[@georgebell3964]

Hey Matt I like your choice of Dr Pepper. Also enjoyed the video

[@SchrodingersBox]

Haha. yeah I find diet Dr Pepper tastes almost exactly like regular lol.

[@Auxbeam]

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[@tomasnokechtesledger1786]

My 1994 Taurus does that with its original EEC-IV fuel injection system. Gives low compresson diagnosis per cylinder!

[@anyheck]

In an Otto cycle engine there's not a negative gauge pressure at the bottom of the power stroke when the engine is running. But here, where there's no combustion happening, there is vacuum at the end of the power stroke. This was unclear around 11m30s where you're describing the combustion cycle. This remaining expansion is wasted into the exhaust. An Atkinson cycle engine ends the power stroke at zero gauge pressure as the power stroke is longer than the compression stroke.

[@fire7765]

Great job

[@JuanHernandez-ov8wv]

Great video .i like others Appreciate All t thinks we have learned from u sir. Much appreciated Crazy how we have become mechanics to technicians to now doctors with these new modern cars. N unfortunately without a scope n a bidirectional scanner. Its really hard to get to t complicated fluke like problems. Thanks for sharing n teaching us. Well guess I got to upgrade to a scope now. If i still want to work on cars. But soon as its all electric cars im out. Lol.

[@SchrodingersBox]

Right on hahah. yeah I have no interest in electric cars either!!

[@testosteroneinc.3800]

I hope this is good! Just so you know, I clicked off the Torque Test Channel to watch this. 😎

[@SchrodingersBox]

This one is good lol. guarantee 100% you will learn something you didn’t know before.

[@sivaromar4371]

Much appreciate it sir!

[@kellismith4329]

It is a great scope it would be worthwhile investment as you can easily fire that much cash out through the parts cannon, and when the smoke clears you still have the tool to use next time

[@jdean399]

Hi Matt, great video, I subscribe to 'the other channel' I would appreciate more pressure waveform analysis, its great info, also the pico is expensive, but auto ditex sell equivalent pressure transducers a lot cheaper

[@SchrodingersBox]

Noted!

[@robertmobileman8304]

Great video ,good content thanks

[@SchrodingersBox]

Much appreciated!

[@Andy-ms9vi]

Have you tried Pico 7? I was avoiding using it because the layout is so much different than 6, but since they made a version for Debian Linux I decided to start using it. Overall, I still like 6 better, but there are a couple cool things about 7.

[@SchrodingersBox]

yes I did. originally I used 7 and I liked it a lot, however then I got a new laptop and there is a known incompatibility with the graphics card and 7 on the laptop so I had to downgrade to 6. obviously I didn’t know that at the time I got the laptop or I would have bought another one lol. But I also agree with you that I actually like 6 better. the UI on 7 feels “dumbed down” to me.

[@jeffreyjohnson3857]

The car has a cracked intake internal vacuum leak the ECM is reading high vacuum pressure when it reads high vacuum pressure it puts to fuel to it because it's tricking it it floods it out look inside or change the intake and see if the car does not straighten out I've had this problem with older Chevrolet's the aluminum intakes they crack internal people's poor big money in tomb we figured it out one day we put a different intake and fixed it

[@nukesploder]

thanks for the video!

[@SchrodingersBox]

Sure thing!

[@InsideOfMyOwnMind]

I think the vacuum nearing BDC represents the compression loss that occurred at TDC. because the loss offsets the zero point. You would not have this on a running firing cylinder. In order for timing to create a rich condition intake air VOLUME has to be EFFECTIVELY restricted but not reflected by the MAF. Excessive overlap comes to mind. Perhaps a stuck advanced intake phasor? I say effectively because although the air is being moved through the MAF and making it into the cylinder it is NOT making it to the compression stroke because too much of it is being blown straight out the exhaust, thusly a loss of effective intake air not revealed by the MAF. You would see this as a high o2 content further guiding the ECM into causing an even richer condition. So while trims might look like it's pulling fuel it's operating on a severely skewed platform.

[@SchrodingersBox]

yeah this was pointed out by another viewer and I agree- waveform would be quite different on an actual power stroke.

[@stuckinmygarage6220]

@@SchrodingersBox Anorher reason I like your channel, Matt! Classroom atmosphere. I wish I was back in school. Cheers!

[@curtgirardin6093]

@@SchrodingersBox One of brandon steckler's videos shows an in-cylinder pressure capture of a Ford Ranger with 2 spark plugs per cylinder. I guess one of the spark plugs is only used during certain conditions - this was replaced with the WPS-500, and the other spark plug left in place; allowing a pressure capture of a firing cylinder. The pressure wasn't as enormous as I would have expected; but at no point during the "power" stroke, did the cylinder drop into a vacuum. This is why the dollar-bill trick at the tailpipe only sucks the dollar bill in when there is a misfire. :)

[@ZoomAutoDiag]

Problem is that the piston is cracked. Combustion leaking into crank case.

[@SchrodingersBox]

HAHAHA. yeah that model was a piece of sh-t lol!!! The best part was the cam lobes were mislabeled too so I had to build it several times til I got the cam timing correct for each cylinder.

[@ZoomAutoDiag]

@@SchrodingersBox lmao better than nothing I suppose. I didn't realize you had to actually put that together. Must have come from Amazon lol

[@SchrodingersBox]

it did lol. $30. it was like 400 parts too and it looks like China even outsourced its production somewhere lol!!!

[@ZoomAutoDiag]

@@SchrodingersBox 😂

[@joecraigslist9467]

Ivan at Pine Hollow Auto Diagnostics has pressure transducers for sale at $375.

[@VentureStJohn]

Excellent video. However, I see oscilloscopes and bi-directional devices in the future of DIYs

[@SchrodingersBox]

Great point! I totally agree 100%. The mentality that DIY’s still use just wrenches and elbow grease is completely outdated. a DIY nowadays needs to be as savvy as a tech was 15 years ago. A DIY who still doesn’t know how to use a DVOM is going to be extremely inept… or they need to keep working on cars from the 1960’s and 70’s which has always been the excuse for not knowing computer and electrical!

[@jesusmalagon4336]

Thanks 😊 master exelent

[@ZoomAutoDiag]

The use of a second channel to show the ignition primary/secondary waveform would be to check ignition timing.

[@SchrodingersBox]

that’s correct. i could easily have done that. however it’s easier to check ignition timing with the relative compression test because I wouldn’t have to remove a coil and plug. all I need is to amp-clamp an ignition wire and battery cable.

[@ZoomAutoDiag]

@@SchrodingersBox good thinking. I've never tried it with RC but I will now. Is that accurate? The humps of RC always seem noisy for accurate measurements. I've never tried it so I'm asking for my own education on that method.

[@SchrodingersBox]

i absolutely trust the relative compression test!! I have run into a few “pinhole” gasket leaks that the compression test failed to pick up- but in general it’s as reliable as a gauge test. also you can filter the signals to clean up noise.

[@ZoomAutoDiag]

@@SchrodingersBox sorry. Let me clarify, I trust it to verify a dead hole. But I was asking about adding second channel to measure ignition timing that you mentioned with RC... I use ignition capture for firing order placement but never tried it for confirming ignition timing being in spec. You said it's easier to do it with RC(checking ignition timing that is) unless I misunderstood. Although this is the second mention, maybe even by yourself, that I've seen this about IGT being checked with RC. I'm curious. Maybe you can do a video if you haven't yet.. if you wish to do any more advanced oscilloscope stuff. I know you like to reach the DIYer rather than do videos with tools a DIYer may not have but...

[@SchrodingersBox]

oh gotcha. yes I absolutely use RC with an ignition signal to determine ignition timing. i know I have this done is videos and in fact just last weekend I used the technique to determine a car running poorly was due to the timing belt installed wrong.

[@sounds5397]

Nice shirt brother

[@Mechanicsville804]

John 3:16 For God so loved the world that he gave his only begotten Son that whosoever believeth in Him shall not perish but have everlasting life.

[@labradormcgraw]

Impressive stuff for sure. But was anyone else more impressed by the toy engine than by the Picoscope? 😂

[@SchrodingersBox]

ROTFLMAO!!!!!!!!! well it was definitely cheaper lol!!!

[@labradormcgraw]

@@SchrodingersBox LMAO I really want one!

[@joeblow6786]

Mad Matt's psychedelic garage running the in-cylinder pressure transducer while listening to Pink Floyd's Comfortably Numb... What could possibly go wrong?

[@joshuaanthony8416]

Awesome video bro, let’s show the DIY mechanic how to check timing with $5,000 equipment.

[@SchrodingersBox]

what $5000 equipment? you mean $500 equipment? is there a DIY who can’t afford $500 in basic equipment for electrical diagnostics when it costs more than that for a pro to do it for you just once?

[@christopherbriden8403]

I think it’s ok to show some technology on the channel. Mistakes are so costly that it makes the technology easier to justify. I would rather spend the money on diagnostic equipment that I get to keep than blowing it on guesses.

[@stevo3644]

Why doesn’t anyone use a vacuum gauge nowadays ? You could diagnose this issue in about 5 minutes without any fancy diagnostic gear.

[@SchrodingersBox]

and how would you do that with a vacuum gauge when the fuel trim compensates for the valve misadjustment? what would the vacuum gauge show?

[@stevo3644]

@@SchrodingersBox - my experience has been the fuel trims cannot adequately fully compensate for valves that are tight and at idle a vacuum gauge will still show an erratic reading leading to help diagnose incorrect valve adjustment. To further confirm this a no start vacuum gauge test can also help. Under crank I have found the vacuum should be approx 3 to 5 inches of mercury.

[@SchrodingersBox]

but you saw it here. the fuel trim compensated. you saw the LTFT normalization.

[@nicholastaylor1546]

That is great - Pine Hollow Auto Diagnositics sells one for less

[@curtgirardin6093]

Hi Matt, just watched your video. I would also consider myself an "advanced DIYer". I also have a Picoscope as well as a WPS-500, and I get super excited anytime I find and excuse.... errrr, /need/ to use them. Have you learned how to work with triggers on the pico software yet? The built in help in the software is pretty good, but I'm pretty sure scannerdanner's pico training video covers them as well. Triggers would help you to stabilize the picture so the pressure peaks would be drawn at the same point each time. Then it would be even more noticeable when the VVT is actuated. kzbin.info/www/bejne/bmKkeJWQmMx2kNU

[@5477harry]

First!!! Hahaha I have no life 😅

[@Kamel419]

second! lol

[@SchrodingersBox]

Lol you guys have no life???? I just spent my whole Friday night making this nerdy video lol

[@5477harry]

@@SchrodingersBox I retract my comment and I stand corrected. Your nerdy as charged my good sir 🤓

[@legallass9905]

Ha! My nerdy, nerdy man.

[@benjamynbrady3443]

Why a kid is in a candy store unsupervised, with $1,300....

[@SchrodingersBox]

Because he built it himself through working!

[@benjamynbrady3443]

@@SchrodingersBox any inclination or opinions as to the potential quality of a hantek 2d82 III? Seems to be based off an old fluke handheld oscilloscope or something

[@benjamynbrady3443]

I know thats a question from the outfield 😂

[@SchrodingersBox]

HAHAHA Yeah that was. i am not familiar with any models other than what I have sorry. i forget what hantek model I have but it’s pretty limited.

[@bartscave]

If you paste the image from the scope onto a in cylinder waveform overlay chart there is an option to calculate all valve events. Free download: www.microsoft.com/en-us/p/pressure-waveform-overlays/9ngwmcx2rmth