P0301 Misfire Is Under Intake Manifold- What Do You Do?

[@technomage6736]

I bought an Autel scanner off the tool truck and recently got into using Power Balance readings on certain models that don't have the individual cylinder readings. VERY helpful function to have. 👌

[@wyattoneable]

I do enjoy your approach to diagnostics. I always learn something.

[@SchrodingersBox]

Thanks so much. And by the way thanks for your many years of subscribing!!

[@StayPositive-sd8op]

Same here

[@JuanGomez_master-tech]

Been loving these videos for more than 9 years, thanks Bro.

[@SchrodingersBox]

Oh wow man I am glad to hear that!! Thanks for sticking with me!!

[@JuanGomez_master-tech]

@@SchrodingersBox I pay for your other channel too, I haven't had time to watch in awhile but... Also watching your videos before taking the ASE L1 makes it so I pass it every time.

[@SchrodingersBox]

Oh wow man I’m very grateful!! Thank you!!

[@MarzNet256]

Awesome. Nothing beats a solid diagnosis like recreating the problem. I was also thinking to check pulse pressures in intake and exhaust using transducer to verify good valves (although compression sounds perfect). Also, if fuel trims could be manipulated with scan tool, that could be useful to unmask a blocked or leaky fuel injector. I just started using a pico 2204a and took an induction waveform capture off an ignition coil (with a coin). The amount of detailed information you can get rapidly and non-invasively with the scope is....mind blowing.

[@SchrodingersBox]

Yes that’s what I enjoy most about this- the vast array or various strategies that can be employed.

[@mandytuning]

I also use a relay and works great.

[@timday4225]

Once again, another effin awesome video from the man who gets straight to the heart of the matter and explains how things work like a master. Brilliant Matt 👍

[@SchrodingersBox]

Oh man thanks!!! I’m blushing lol.

[@timday4225]

@@SchrodingersBox credit where credit is due buddy 👨‍🔧

[@tylernelson8987]

Hey Matt im working on a Bravada with a misfire issue and I just watched your videos you did a long time ago with the Blazer going through the diagnostics steps. I was hoping I could somehow chat with you either on here or through email and pick your brain a bit. As it's very clear how intelligent and experienced you are. Hope to hear back from you and can pay you for your time. Thanks, Tyler.

[@SchrodingersBox]

Happy to answer any questions here.

[@NickMyers1]

That 24 valve dual overhead cam motor is very famous as I know you know for ignition oils failing. Not just from spark plug where but also from extreme under hood heat in certain climates. Enjoyed watching your diagnostics. One day I need to add a pico to my diagnostic tool set.

[@Jason-cu1jp]

Another great video! Lets not forget a parts changer would have likely replaced at least the three rear injectors too, likely with inferior ones. I love secondary waveform analysis. Such a quick, easy test to see whats actually going on. The only annoying thing is when I'm doing it and "more experienced" people watch on like I'm crazy. 😏

[@SchrodingersBox]

totally agree!!

[@gordonstarship]

If that's my Freestyle. I'm grabbing the hole saw kit and making a window in the firewall. Ford's access panel they should've included. Excellent video. I love your passion for using science to find the route cause.

[@mtrltoolman]

Good job. LCR Meter is the best tool for measuring the resistance of coils and capacitors . It is send high frequency instead of low current dc voltage in resistance measurement mode in Multimeters

[@SchrodingersBox]

Great advice someone else mentioned this too.

[@allenbarker3003]

I have a 1999 chevy venture 3.4 v6 van. Turn over no start, but acts like it wants to start, but has a slight backfire. On the end of stopping your turn of the ignition key. I have changed cam shaft positioning sensor. The wires just pull out of the top of the sensor. I am older man now a days it takes me a lot longer to try and do this work anymore. But I don't trust auto shops. You are a genius

[@glenntagaylo2339]

Finally learned something especially not to rely on the multitester reading of the coil because it's different under load. This applies to other electronic stuffs. Also teaching me to think through first. Awesome troubleshooting sir.

[@advancedleveldiagnostics]

I can't believe you didn't show how to remove the intake😜🤣 Great job as always!

[@beninchesapeake]

Another great video. Although your method of actually diagnosing problems is more time consuming than simply firing the parts cannon. I'm sure it is greatly appreciated by your customers.

[@SchrodingersBox]

How is it more time consuming than firing the parts cannon? If this car was misfiring due to a ground fault on the injector, how would replacing injectors, coils, plugs, and R+R an intake manifold be faster? That would be over 5 hours of labor and still not fix it.

[@beninchesapeake]

@@SchrodingersBox Maybe I said that wrong. I just think it's admirable the way you do the extra steps to perform a proper diagnosis.

[@jgeorges3061]

Matt, as always thanks for ur time and knowledge been sharing even I know most of this staff but still I watch ur videos because ur a great guy by helping other people fix there cars the right way cheeeers brother.

[@SchrodingersBox]

Thanks as always my friend!

[@highlightfactory7588]

Just had this problem occur yesterday. Thanks for the video!!

[@joecraigslist9467]

Why do Topdon, Launch, and ThinkTool seem to be running the same software? Is there something special Topdon has that ThinkTool doesn't?

[@deerhunter8533]

Topdon, ThinkTool and Kingbolen use the Launch software.

[@weldingjunkie]

These are facts I’m about to tell you. Launch brought their software. We had it for a long time. Erik left lunch to open ThinkCar. he also went to the same company and had his software built with similar options and features. Thinkcar is the OE for topdon. Topdon buys thier software from thinkcar and used to buy same tablets too. Topdon is slowing starting to make there own cases / R link and j boxes. Again this is all factual. The company that sells to launch and thinkcar won’t sell direct to topdon. Chinese thing.

[@weldingjunkie]

@@deerhunter8533that’s not true.

[@weldingjunkie]

@@deerhunter8533topdon has nothing thinkcar doesn’t except for battery stuff. Scope is 100% from thinkcar

[@abdul-kabiralegbe5660]

​@@weldingjunkie Hmmm. So it's better to go with Launch since they seem to be the closest to the source?

[@JohnDoesGarage]

There is nothing like a scientist using the scientific method while troubleshooting, along with common sense. I am a firm believer in preventative maintenance. Depending on the age and mileage of the car, the cost of the parts, and the labor involved, it is absolutely prudent to change parts that are still working but logic dictates they are fatigued relative to the part that failed. In my humble opinion, it would be a disservice to the customer if the other parts weren't changed, that is if they can afford the higher cost and are planning on keeping the car. My customers appreciate forward thinking that may cost more upfront, but save them more money in the future by not needing to pull the manifold potentially two more times as in this example. Not only do my customers appreciate it, but they expect that level of service from me, as they should. Thank you for another great video.

[@SchrodingersBox]

Great comment man!!

[@tylernelson8987]

Hey

[@gcrady]

Talk about random luck ,, My 2004 Mazda MPV is going to the shop for the exact same issue/diagnose. I hope I can ask the technician to have a look at this video.

[@rwrobs777]

Hey Matt !!…C5 Diag here…great video !!…don’t know if have ever used the WPS in the tailpipe to VERIFY that your misfiring cylinder is the one that is actually showing on the scan tool…sometimes that misfire can be a companion cylinder or the cylinder before or after the one in the firing order…like to be 200% sure.

[@SchrodingersBox]

Hahaha I know who you are man lol. Like I would ever forget. Yes I believe on my pay channel I did a video where I used exhaust and intake patterns to verify a misfire.

[@embreesmith7613]

Bernie !! New Content..fantastic. 🙂🙂🙂

[@SchrodingersBox]

Thanks as always!! Some new concepts shows in this one

[@bilaltarhouni4142]

As usual, great video. We need a video for Evaluation of a working mechanism of spark plugs.

[@SchrodingersBox]

I have one!!

[@bilaltarhouni4142]

@@SchrodingersBox Please give me the link of the video.

[@davidebare3401]

Great informative video. I’ve learned so much through your channel and just invested a good amount of money in a picoscope. Hopefully it can pay for itself real soon😊

[@SchrodingersBox]

Oh man congratulations!!! It TOTALLY pays for itself. The fact I can charge a 1 hour diagnostic and use the scope to determine a cause in 15 minutes is a huge revenue generator. Plus my improved speed and accuracy means I get more customers. It absolutely is a great investment with a fast ROI.

[@Christdeliverme]

Thanks for the video my man.

[@sheerwillsurvival2064]

Yeah he’s back 👊🏻

[@ThunderbirdRocket]

👏🏼

[@ozzstars_cars]

Did the tune up cure the long term fuel trim issue?

[@SchrodingersBox]

I never checked because the LTFt was not really out of spec that bad. Since bank 2 also dropped fuel trim a bit under load it’s clearly something non intake manifold related but I’m not concerned about it.

[@danielcruz-xb8mq]

Nice video. Thanks for sharing your experience and knowledge. Gracias por compartir con nosotros 😊

[@weldingjunkie]

Another good video Matt great job. Sometimes we don’t win on the jack pot tho lol no comm or pre auto vin. Just teasing here.

[@ThadrinC]

Great video! Next time I would suggest running a relative compression test for the raw data. For me its scan, if misfire is present in one cylinder run ralative compression, then check the coil the same way you did. Takes like 20 minutes for all tests max.

[@SchrodingersBox]

I would have run relative compression if there was any indication it would show positive. You can clearly hear there was absolutely no compression loss in any cylinders. So I move it to the least likely cause. Also the fact the misfire wasn’t consistent further substantiates a compression issue is less likely. Otherwise I totally would have done one.

[@BblastedD]

Grizzly Adams in the shop.

[@SchrodingersBox]

Hahahahaha. Yeah my beard doesn’t look good if I don’t comb and brush it lol

[@ThunderbirdRocket]

Looks like a hockey player ! 👍🏼

[@HOTRODRICO]

@@ThunderbirdRocket playoff time lol

[@ThunderbirdRocket]

@@HOTRODRICO Yep ! Focused and ready to get ‘er done !

[@johnshinski2994]

great video thanks

[@woody95124]

Very very good job bud..wow

[@SchrodingersBox]

Thanks man!!!

[@John_Rod]

Very informative video, although I have seen clogged injectors that caused a misfire with the LT and ST under 10 percent. After that experience I usually try not to rule out clogged injectors

[@SchrodingersBox]

I actually have never once seen a clogged injector however I have a video of an injector with an open winding. We can see from the secondary in this video that it is not a fuel issue. A fuel deficit shows a very specific “double firing line” on the secondary due to the higher resistance in the cylinder without the conductivity of the fuel.

[@dcengineering6238]

Wow!!!! You are awesome!!!

[@ianmoberg374]

I love ur vids man they always pop up after I watch a vid for my tdi and I end up watching for a while, I've been wondering what is the can bus system in a dummies down explanation lol when I look up what it is it's kinda confusing

[@SchrodingersBox]

I have an explanation of network systems and how to diagnose them on my paid content channel at www.schrodingersboxqm.com. Most of it covers CAN.

[@philh9238]

During the ignition waveform analysis I used to see on the old caprice opti spark when the burn line sloped down it was the spark plug.

[@paulpaquette1961]

Good work buddy!!!

[@SchrodingersBox]

Thanks!! This one totally surprised me indeed.

[@rodvan-zeller6360]

Excellent video. Did you have a relative compression test mode in the scan tool? Did scan data have ignition burn time per cylinder? Ohm meter test, if it shows good it does not mean anything, if it shows bad it is bad. Have you tried to make a trigger circuit with a TTL 555 to bench test coils? Thank you in advance for your answers. .

[@SchrodingersBox]

Yes there is a relative compression test mode but I usually just set my ammeter to volts with a 2s timeframe rather than go to it. In this video it was so obvious compression could be ruled out I didn’t even do a relative test. I do have a video on bench testing coils.

[@rodvan-zeller6360]

@@SchrodingersBox Thank you for the reply.

[@calholli]

My xtool D8 has topology too.. It didn't have it when I bought it.. But they added it later as an update; which was a welcome upgrade to receive for free. :)

[@SchrodingersBox]

Oh wow good to know!!!

[@DependableAutoTruck]

great job good video thanks for sharing

[@SchrodingersBox]

thanks howard!!

[@r.weaver3769]

I have also found the ohms test wrong on several bad coils on different makes. Would you not address the vacuum leak too?

[@SchrodingersBox]

I addressed the vacuum leak off camera since it wasn’t relavent to the main issue.

[@PeterHernandez-lg2eh]

Maybe this is my problem. Po302 on my 2006 Subaru sti. Did the swaps, compression and leakdown test, noid pulsing test,crankshaft and camshaft position sensor test and cleaning. Used smoke machine to detect vacuum leak intake and exhaust sides. Very frustrated

[@SchrodingersBox]

Maybe it is. An easy way is to just check amperage on the coil. Coils are easy to access on Subarus.

[@donkaiser6704]

Like watching a murder mystery unfold. Thanks!

[@TheJcman72]

Since there is no resistance difference between a good and a bad coil, it can't just be a coil. Is there any electronic circuit inside that plastic packaging that could explain the bad behavior during operation? Or is it just temperature related issue? Could you test the coil resistance after warming it a bit? Or since it's bad, tear it apart? It would be nice to understand what really fails inside the "coil".

[@SchrodingersBox]

No there is a massive resistance difference between the good and bad coil when the coil is under load. when the coil is not under load, there is no difference. this is why I mentioned ohming a coil is a terrible way to test it. you have to always test any coil when it is under load.

[@DependableAutoTruck]

what are the odds i have the same car same color in my shop few months ago fixed ac , alternator, passenger side axle and now the cvt transmission quit so they said enough junk it. so if you need anything hard to find i have some parts.

[@SchrodingersBox]

hahahaha. this car had a similar history!!! An elderly couple bought it off a lot a few years ago and they have spend thousands of dollars on repairs before they found me and even since finding me i have done maybe $2000 of repairs on it in the last year.

[@ryankeller8542]

Videos are very informative. Even admit hypocrisy by mocking people for changing parts because "it needed it anyway". And then prove they didn't need the spark plugs. So much time spent mocking in this video. I guess admitting the irony is refreshing.

[@SchrodingersBox]

it’s not irony. they did need the spark plugs because the cause of a coil failure on this car is spark plug excessive resistance. you would never under any conditions change a bad coil but not also change the plugs and wires as well. it’s not “they need it anyway” because i made a mis-call or an ignorant guess. it’s “they need it” because i accurately determined a coil failure which means it’s standard procedure to replace the secondary ignition components responsible for the failure.

[@ryankeller8542]

I don't think you were wrong to suggest changing the plugs. Maybe you already knew they needed spark plugs when filming. Video, as watching, you said it was most likely. I appreciated calling yourself out. It was refreshing. I have learned a lot (especially fuel trims) and will continue watching. Thank you.

[@TheJoeScarafoneChannel]

cyt.....geezus

[@rexisretro]

Just got a topdon great value

[@SchrodingersBox]

Totally agreed. As powerful as a snap on verus!!!

[@calholli]

What paddle probe did you use to test that coil? Do you have a link for it?? to buy it

[@SchrodingersBox]

I have several of them that I just got off Amazon. various brands.

[@calholli]

@@SchrodingersBox You could do a video comparing all the paddle probes you have.. (maybe you have, I"ll search the channel).

[@SchrodingersBox]

@calholli no I haven’t. But I have Three of them- they all perform identically but some are longer and less flexible and others are shorter but very agile. Just depends on what I am trying to reach.

[@maradallibya5791]

Great! But what is the plan if you couldn't approach for the coils under the IM?

[@SchrodingersBox]

I have several different probes that would fit under even tighter spaces than this however what I would do if I couldn’t access the coils is I would dissect the wires out of the wire harness and measure amperage on the ground side controlled wires for the coils. This would be a bit time consuming but still faster than digging out the PCM on this particular car.

[@maradallibya5791]

Thank you for your reply, great idea

[@maradallibya5791]

What if in that situation we took the amperage of all the fuel injectors and ignition coils in one screen, couldn't it tell us something important and quick, even you said that it would be very busy in the video?

[@bobcombs7138]

​@@maradallibya5791 In the video he was considering that. But while looking at the wiring diagram it was discovered that there are too many other power consuming devices on the circuit to accurately pinpoint that coil. He then decided to use a more direct approach which was actually the best way in this situation. His critical thinking was the key.

[@SchrodingersBox]

Excellent summary!

[@calholli]

I agree... I would strongly recommend to replace the three coils in the rear... and keep the two good coils for spares.. which you can swap back into the front bank if they ever go bad.. and save them a little money on buying new coils later; or maybe the old man could even swap it himself (on the front bank-- in the future)..

[@SchrodingersBox]

Exactly what we did!! Seemed the most economical and reliable way to do this. New plugs too!!

[@ThunderbirdRocket]

Hello Matt ! Happy Sunday evening to ya’ ! 📈🔥💡 I want to ask you if you can help me understand where initially the symptoms and especially with fuel trims pointed to a vacuum leak and in reality (ultimately) those were caused by this failed ignition coil . If you don’t mind .

[@ThunderbirdRocket]

Wait / hold on . I’m now aware (after watching the video again) that a vacuum leak might exist but AWAY from the intake manifold which was sprayed down. Am I understanding correctly / was there any vacuum leak at some other location ?

[@SchrodingersBox]

Correct. Somewhere is a vacuum leak affecting both banks but it’s minor and irrelevant to the issue so I am no worried about it.

[@ThunderbirdRocket]

@@SchrodingersBox Got it ! Thanks for the quick response ! Much appreciated ! 🐱🎁 ⛰🔥 Schrodingers Box Rocks !!

[@JrSpitty]

Without turning a wrench how would you verify the PCM driver is OK? Like you said without the proper load you wouldn't know if the ignition coil is bad simply by resistance checking it. Just curious what you would be looking for. Personally I dont mind taking off an intake manifold to do some additional checks as i find its typically much easier then it looks at first glance, lots of technicians psych themselves out into making a 5 minute job seem like a whole day ordeal. Good work though going through it without having to take it off! :)

[@vernhood4568]

If you want to verify that the PCM driver is ok just backprobe the control wire at the pcm and look for control with a scope.

[@JrSpitty]

@vernhood4568 but with a bad coil you don't have a load. Usually a coil takes out the pcm driver. The plug gap goes out of spec which overwork the coil then overwork the driver in the pcm. The driver in the pcm is simply providing a ground. Which is easy to do when there is no load on the circuit.

[@vernhood4568]

@@JrSpitty Then put in a load like a test light that isn't to large for the driver to handle. I've had noid lights work when the driver was bad because it doesn't pull enough current.

[@PeterHernandez-lg2eh]

Got the xtool ip 819 bidirectional scanner hope it has the functions I need

[@SchrodingersBox]

It certainly should

[@abab201]

Hello i need help with this exact code and even worse Mechanic already installed rebuilt starter, new rotor and cap, fuel filter, pump relay, spider, spark plugs and cables within the last 30 days, new fuel pump and assembly less than a year ago but i always run it on empty so it MIGHT be bad. He hooked up the guage that shows the pressure is over 60 and doesn't bleed down until hours later. He doesn't want to charge me to do the fuel pump because he knows I'm broke and doesn't think that's the reason my 97 ahhsshole van won't start. That's the question, does anyone have any ideas? It needs starter/carb cleaner to start after 4-5 hours sitting, then i can run errands all day, but IT WILL NOT START after sitting more than 4 hours during the day or overnight, temperature outside makes no difference. Only code its giving is the same as this video. Mechanic says that'll cost more than the can is worth, right now i just need it to start reliably. Taking it to a guy who thinks it's the computer and has more testing diag tools than my mechanic next week. Any thoughts are much appreciated.

[@SchrodingersBox]

Unfortunately there is no useful data here. I need to see the fuel data, the timing data, the ignition data and induction metrics data.

[@abab201]

@@SchrodingersBox thank you for the quick reply. Are you anywhere near southern California or know anyone as good as trustable as you in southern California?

[@SchrodingersBox]

Sorry I am not. I am in Colorado.

[@chrisdaniels4674]

Don’t let the comments get you down. Ignore the idiots.

[@tomtke7351]

Common voltage feed to injectors AND coils but don't they trigger at different times... i.e. bank 1 injector is followed by bank 1 coil? Intake/compress/ignite/expell... So scoping that common while triggering on front #4 injector would I.D. the cylinder sequencing?

[@SchrodingersBox]

Yes of course we could have done that but the issue is having all 12 events at one time is very busy on the screen especially considering you get THREE firings for each coil plus some feedback from the coil and injector firings as well. It would have been an absolutely mess trying to verify and identify the signal voltages alone, much less the specific cylinder. So much easier to just do the single coil trace like I did on this particular design.

[@tomtke7351]

@@SchrodingersBox i'm certain you're right but the injector firing comes well before the triple firing of coils... -Intake... injector firing -Compress -Ignite... coil firing -Expell... And yes! It would be busy....

[@tomtke7351]

FOUND ON INTERNET: /////----- The time between injection and ignition can span nearly a full engine revolution, as injection occurs during the intake stroke and ignition near the end of the subsequent compression stroke. -----/////

[@tomtke7351]

I'M suggesting your first inclination was brilliant but the later discount without trying was disappointing. I wanted to see the current draw waveforms... -Tom

[@SchrodingersBox]

I will definitely show this at some point when I get a car that will give a “cleaner” signal so I can show how we analyze and identify each cylinder.

[@sheerwillsurvival2064]

I just gotta do it I know it has nothing to do here but it’s stuck in my head. GROUNDS !!!!😂😂

[@SchrodingersBox]

Hahahahaha yeah I couldn’t work that into this video lol

[@PeterHernandez-lg2eh]

I will keep at it for now.

[@calholli]

The coil windings can still be good.. but it's just arcing through the insulation and shorting to the block somewhere.. Sometimes you can just replace the rubber boots, if you can find them... and if they are easily removable. (nice diag, as usual)

[@SchrodingersBox]

Yes totally agree and in fact probably what is happening. However there is no way I am only replacing the boots if the coil is under the intake. That coil is being replaced for sure to prevent a comeback!!

[@calholli]

@@SchrodingersBox I agree.. that's a good call. But as a DIY on my own stuff... I might swap a boot if I could get them. :) .. too frugal for my own good.

[@ignacioromero5014]

ok so whatever it is (a component) it makes sense to replace all of them if they are the same age. Oooorrrrr you can have them go off one at a time. I get your point though from an upsell perspective.

[@geoepi321975]

Hi , what is a misfire, an incomplete combustion because of weak spark, or something else

[@SchrodingersBox]

it is a failed combustion event for ANY reason. weak spark, lack of fuel, lack of compression, lack of oxygen, bad timing….

[@geoepi321975]

@@SchrodingersBox thanks for reply, how can we diagnose it on a single cylinder carburettor scooter, is low compression a reason of misfire or loose timing chain, cause I have black spark plug, and changing the main jet with a leaner one it became worse thanks

[@SchrodingersBox]

Oh man. On a scooter with one cylinder it wouldn’t run at all if it was missing fuel or spark. It had to be either timing or low compression. Since it’s one cylinder you have to compare compression to a specification- you can’t compare it to another cylinder. Keep in mind bad timing will cause low compression. You probably will have to disassemble it to check the timing marks. OR try putting about a tablespoon of oil in the cylinder and if compression increases you know the piston rings are worn.

[@geoepi321975]

@@SchrodingersBox thanks for reply, the manual calls for 170 psi and I have 93 psi and if I put a spoon of oil it goes 130 psi I don't know if my chain is stretched

[@SchrodingersBox]

Yeah this confirms the cause of your issue is low compression. It’s a little unclear where the loss is and if it’s a timing issue. This is where you just have to start dissecting it but at least you know this is 100% a mechanical issue.

[@pamelavance648]

30 yr old car.. does the needed it anyway apply ???

[@SchrodingersBox]

no. because you still have to fix the cause of the problem- that’s the objective. it’s not maintenance. it’s repair.

[@pamelavance648]

@SchrodingersBox I was being silly 🤪 Love my subyroo and trying to keep it going.. watching learning and thank you for your information you share 😊

[@user-hr5dc4ly3q]

I love you man a feal you are my brother😊

[@SchrodingersBox]

Same!!

[@crispusb]

One could use a LCR meter to measure the inductance of the coils (also useful to measure the capacitors)

[@SchrodingersBox]

Yes indeed. Other mentioned this too. Much better representation of a device under load.

[@YNARUTO97]

Nothing beats a picoscope with some knowledge

[@SchrodingersBox]

That picoscope is the second most powerful tool after my scantool. I use it more and more as incontinue to expand my knowledge.

[@TheGeno2001h]

Sir I got question I have 2010 Chrysler Town and country 3.3 I change everything I mean every part ac not getting cold only when the car is moved or when I accelerate at the park i take it to 2 mechanics no know why if you can help cages reading 45 on low 230 on high like I said working fine when I’m driving? Sorry if I missed any spell anything wrong English is my second language thank you

[@SchrodingersBox]

It could be a ducting problem and the AC is never channeling through your vents?

[@jessecamacho5797]

Maybe bad replacement parts, orifice tube installed improperly or bad expansion valve, depending on what you have. Possibly not vacuumed?

[@SchrodingersBox]

If it’s a bad orifcace tube or expansion valve how would you explain the 45 low side and 230 high side readings?

[@TheGeno2001h]

@@SchrodingersBox It is but it only gets cold when I drive. As for the ducting problem, it’s not because I can feel it.

[@TheGeno2001h]

@@jessecamacho5797 It doesn’t come with a tube. It comes with a drain. I already replaced it. I vacuumed twice.

[@vernhood4568]

If the coil wasn't working you wouldn't have any or a much lower signal. Also you are looking at it upside-down. If we could see the whole capture we could break down what is exactly going on.

[@SchrodingersBox]

Both of those statements are incorrect sorry. We clearly see we have signal. It is undeniable. And it is irrelevant if the image is inverted.

[@vernhood4568]

@SchrodingersBox Then explain why the signal in the bad one is bad and give before and after of the good to bad coils like you do when doing cam crank comparisons. I've been reading ignition waveforms for 20 plus years, and that 's the only reason I am responding to this. I don't like being told I'm wrong without an explanation, and until you prove me wrong, it's just a difference of opinion. From what little I am seeing of the waveform spark IS occuring, but it may be happening somewhere outside of the cylinder. That's why replacing the coil and moving it somewhere else made it appear that it is a COIL problem when it may have just been the boot with carbon tracking. I'm not trying to argue, just want you to be as thorough as you usually are.

[@SchrodingersBox]

Simple. The signal is there from the PCM. You can see it. The VOLTAGE TRACE is bad- showing an obvious open in the secondary but the PCM signal is there. Remember- the PCM closes the ground for the primary. We can see from the bad coil there is a primary signal- if there wasn’t we would see nothing. The very fact we see a signal but it was erratic means the PCM has to be good. There is no other way that can happen. Therefore we know this is either a coil fail. I suppose it could be a spark plug issue but the spark pattern is showing an absence of spark under load consistent with a secondary coil failure. Knowing 100% certain this is a coil failure is clear from the scope trace. It was also proven at the end of the video when the bad coil gave misfires when installed on a different cylinder. It wasn’t even necessary to do that though given the obvious nature of the scope trace showing the coil failed and it wasn’t a spark plug issue. If I moved the coil and it didn’t fail in the new position I would say you have evidence.

[@vernhood4568]

@@SchrodingersBox "It wasn’t even necessary to do that though given the obvious nature of the scope trace showing the coil failed and it wasn’t a spark plug issue." Explain why the scope capture shows it is a bad coil. You are just saying it is bad without showing what parts of the waveform is bad. How are we to learn what good is if we don't know what we are looking for?

[@SchrodingersBox]

I have many many videos of scope traces in my ignition training series. Therefore I did t revisit them.

[@tillman40]

Fords from that period love to break coil packs

[@nickayivor8432]

Enjoy your weekend with all your family around you, Schrodingers Box Can't wait for the next video 👍 WHIP SMART, Schrodingers Box Take care, my mentor KNOWLEDGEABLE,,Schrodingers Box From Nick Ayivor from London England UK 🇬🇧 ⏰️22:46PM Good Evening

[@SchrodingersBox]

Hahaha love you comments Nick!!

[@roundcornerent]

The parts slot machine lmfao ..😄

[@mandytuning]

Another method since this use dumb coils is to back probe from the ecu or from a harness connector .

[@SchrodingersBox]

Yes I was going to do that but the ECU is behind the glove box. No way I’m crawling under the dash for that.

[@rrmech11]

Hey 👋

[@SchrodingersBox]

Hey Richard great to see you!!

[@tomtke7351]

Anymore.... diagnostic fee is appropriate.... 21st century requires 😢 diagnosis! And it ain't free!

[@billyfox384]

Wow... Common theme with his videos seems to be everyone is a hack, except for himself. Couple quick points, the intake R/R is 2hrs labor. Which is generous. So the $700 figure thrown out there is way off. Also, what happened to the For Sure vacuum leak? A misfire caused by a vacuum leak will only be at idle. So driving the car would be and is always a 1st step. Fuel trim readings can be very misleading with a misfire. Next point, the PCM/ECM is not inside the car. It's in the cowl, AND they fail very often. So your time saving techniques are nice, but what if the PCM is sitting in a pool of water? Or what if it would be in water because the drains are clogged??? If the PCM is bad, the proper fix is ALL the coils ALL the spark plugs and a PCM, and they need to be Motorcraft OE parts. I'm not a flat rate tech, but I was, and I can tell you its the system more then the techs. You simply can't spend the time required to properly diag a car. You have zero pressure on you, no customer in the waiting room, no advisor asking you how much more time, or whats wrong with the car. You don't have 8 other cars that need to be looked at. Perhaps you should just do your diags for your customers and your You Tube fans, I think thats great, and you likely help educate some folks out there. But stop throwing the rest of us under the bus. We are not all hacks or dishonest, in fact I think the overall majority of techs want to do things properly. We are all very impressed with your knowledge, if thats what you need to hear.

[@SchrodingersBox]

I am fine but it sounds like you are the one with the butthurt ego and felt the need to try to one-up me. I hope you feel better now even though you failed laughably.

[@billyfox384]

@@SchrodingersBox Honestly I like ur videos, for the most part. I just can't subscribe to anyone in this field that continues the false message that shops suck, techs suck, etc. It has to stop. We all starting working on cars because we loved it. We all at some point wanted to fix peoples problems. Thats a great thing... My point should have been, you can use your knowledge to teach the techs that don't have ur knowledge. NO I'm not butt hurt at all, My shop is overflowing with work and 5 star reviews, just feel for the guys in bad situations. There is a difference between lack of knowledge and being a "rip off". I hope perhaps you can find a way to produce videos without making the public hate going to any shop but yours..

[@videosplus7750]

Not sure why you spend a big chunk of time on your videos criticizing other mechanics....is it some sort of grandiosity? Most people watch your videos to learn a few things not to watch the nonsense mockery .

[@suntoritime]

He criticizes mechanics that have not taken the time to learn essential diagnostic skills. "Mechanics" that have zero ability to diagnose have given the industry a bad name. I really don't think they should even be called "mechanics" or "technicians", just parts changers.

[@SchrodingersBox]

What Justindavis said. Exactly. Yeah- I am absolutely going to criticize a parts changer who charges $700 to an elderly couple which represents half their monthly income to misdiagnose their car, charge them anyway, and also charge them on the next guess as well. Yeah. I am going to criticize that. Especially when a DIY can diagnose it in 15 minutes.

[@NextLevelAutoDiagnostics]

Most of my customers are owners who have been to multiple shops and the problem is still there. WHY? Because most shops only know how to change parts.....and thus should be criticized.

[@stephenmaas8775]

Is this non binary wet wipe for real... This Mechanic is every drivers wet dream! Having him work on your car would be like winning the lotto! I cant bare trips to the garage and family members explaining Wild West ass bandits ripping them off exactly how this guy explained!!

[@travissheehan6082]

Because that’s what will happen to most people-the parts cannon operator will charge the customer for “diagnosis” by replacing unneeded parts. This is a ripoff and morally wrong, whether it is ignorance, laziness, or incompetence.