Full diagnostic procedure on a misfire by home mechanic using logical, systematic approach instead of the common 'parts changer" approach.
Пікірлер: 215
@Renierius10 жыл бұрын
Thanks a bunch, I think that this taught me everything I needed to know to get my '89 Camaro running for the first time since I've owned it!
@kimbeasley8910 жыл бұрын
I did exactly what your video said I had the second mark aligned with top v mark and 1st mark around the 4-5 o'clock position on the side mark. then set rotor button to 6 next to hold down bolt...nothing. went tdc again and set rotor to the 8 mark....nothing......then read that older 4.3L and marine engines have to be set tdc then rotor button to #1 spark plug wire on the distributor cap...I tried that and it worked just fine lol. Im thinking someone blew the 02 engine and stapped an older model block with new accessories in it..... thank you. this video helped me achieve TDC. I always thought the second mark had to align with the bottom v mark on timing cover/crank sensor bracket.
@matthewmcmullen3742 жыл бұрын
Never heard of you untill today thanks Google!!! I will definitely only watch ur videos if they are what im dealing with i love that u dummied ur videos for even newbs awsome job matt ( not a newd)
@michaelstevens20727 жыл бұрын
Your vids are very good ...helped me a lot working on my 2001 blazer....good job my brother and thanks
@SchrodingersBox7 жыл бұрын
Yeah those vortecs are still some of my favorites to work on. nice friendly design and i see them all the time around where i live.
@alexcea16284 жыл бұрын
The examples of what to do is for me a real pick , and now I can wrap my mind around what I need to do when I get a car , I will be wired to deal with my fears about car repairs
@Dannyaudio694 жыл бұрын
You by far are the best mechanic on here. U helped me so much thank u
@SchrodingersBox4 жыл бұрын
Wow, thanks!!!
@Dannyaudio694 жыл бұрын
@@SchrodingersBox if u live in pa. By any chance. I would use u as my mechanic
@carlbuckholz14894 жыл бұрын
I had a P0305 code = cylinder #5 misfire. I replaced the spark plug and wire for $9. Solved my issue. 2001 GMC Jimmy 4.3 V6 142,725 miles.
@SchrodingersBox4 жыл бұрын
How did you know the plug and wire was the issue? Did you just guess? And which one was it- the plug or the wire?
@kellismith43292 жыл бұрын
Very informative video! I have the same engine in a pickup truck, your explainations of the system are spot on thanks I find it really hard to get my straw to contact the piston and see it move while I turn etc
@isaacb49555 жыл бұрын
Once you said its a truck I started scrolling to a video for my exact and specific car. But then...you explained your approach so you got my thumbs up and watching your video in its entirety.
@SchrodingersBox11 жыл бұрын
Ben, Technically, not exactly. When you feel your finger being pushed away by an unmistakable air pressure that means you're APPROACHING TDC (i.e. you're on the compression stroke). To actually get to TDC you either need to stick a screwdriver or something (I usually use a straw because it's softer) into the spark plug hole and see that it reaches its highest point. Or on some models there is a visible mark on the crank pulley and a timing scale that you can line up to be sure you're on TDC.
@kimbeasley8910 жыл бұрын
I will be checking vacume lines and coil soon about that low rpm miss.thank for all your advice.
@alfonsovillafuerte82903 жыл бұрын
I have aproblewm with my 4.3 too. Thanks for the right procedures to follw and remove the no.-5 missfire thanks.
@mrkattm10 жыл бұрын
Your first clue should have been that the Long Term Fuel Trim was at 25% (assuming that you were in closed loop), that means you are running lean. The next question is what does the LTFT look like as RPM go up, it if comes back in line than look for a vacuum leak. I am off to part 2 now to see how this works out.
@SchrodingersBox11 жыл бұрын
Thanks Dave for the feedback and I've appreciated your other comments as well. I have a very basic setup and often I forget to turn the lavelier mic on causing the bad audio, I then artificially increase the volume during editing which makes it worse, lol. I have decided to invest in a professional wireless system anfd future vids will have better audio. These are my first vids and I'm learning both as I go and also from constructive feedback such as yours so I thank you, Dave.
@user-tz6bh1tr9m5 ай бұрын
Your awesome for everything diagnostic thanks man I have a 1991 Dodge stealth twin turbo with no spark it a combo crank cam sensor with infrared laser slot distributor crankshaft cam sensor hybird
@my1after9096 жыл бұрын
Hi! I just watched the path of this vehicle's repair. Fascinating, but at the same time a bit of a daunting process. Long story, short, I've just "inherited" my son's 2000 Jimmy. Great body, great vehicle, but with odd engine problems. I've just put it on the road, and will look into whatever issues show up. I'd prefer to do as many repairs as possible myself. A peculiarity here, is that I've just lost my 36 y.o. friend, and mechanic, to suicide. A frightful loss, which no one has an explanation for. He had been operating his father's garage, single handedly, for the past 7rl years. He was very close to his father, who often lent his expertise, and hands, to the business. Some have speculated, that he wasn't all that interested in "turning wrenches", though he was good at it. That may be the case. We'll never know. The reason I mention this to you, is that it appears that you have a passion for this work. I'm a back yard mechanic, working on only my own stuff. So far, I'm limited to basic mechanical things. Looks like you are similar, but with a much keener insight into the vagaries of more sophisticated systems. Anyway, just wanted to say hello, and thank-you for the informational videos you are sharing.
@SchrodingersBox6 жыл бұрын
Sorry about your friend man. terrible. Hopefully you carry on in his honor!
@my1after9096 жыл бұрын
Thanks for the kind thought!
@Richardbob69 Жыл бұрын
Fuel systems are "a little kinky" hahahahah thank you sir. I just finished replacing the spark plugs wires distributer cap rotor ignition coil and I'm still having a misfire. Wish I had a tool like this but I just wanted to say thanks for the laugh
@lizzagon1410 жыл бұрын
Schrodingers Box I'm having a multiple misfires in my 2007 Suzuki Forenza. The car started to sound weird about a week ago, but no engine light. In the middle of an intersection two days ago, I lost acceleration, engine light started to blink, and the car started to shake. After hooking up a scan tool, I got 6 codes. TWO P0300, TWO P0301, and TWO P0304. All of this read as "random/multiple engine misfire." This is a 4 cylinder car. I took the spark plugs out, and I noticed that in the 4th cylinder there was a very small amount of engine oil on the end of the spark plug and on the top of the piston in the cylinder. Also, I took the oil cap off and the oil smells like gasoline. Please shed some light on this issue... I need to fix this car but I do not have the money right now to take it to a mechanic. The coolant tank doesn't have a fuel smell to it, by the way. Thank you!
@raybridges27387 жыл бұрын
Hi Matt, I recently viewed two of your videos in order to learn how to properly install the distributor in the 4.3 liter GM engine. My need to do this was a result of my intake gasket replacement project. I performed this on a 2000 GMC Safari van and was doing great until I got to reinstalling the distributor. I know how to correctly find TDC (because I've done it many times now following your instructions) but no matter how many times I install the distributor, carefully aligning the dimple with the white mark on the distributor shaft, the rotor button pick up is always pointing about 1/4 inch to the right of the number one cylinder mark, (arrow with the 6 on it). When I attempted to start the engine in this condition, it would run maybe a second or two. And additional starting attempts just caused the engine to become flooded as I could smell the gas. And after that, it's not going to start. Obviously, I'm doing something wrong in the distributor install sequence. I have been aligning the oil pump drive with the drive blade after turning the shaft dimple to the white mark. It's the only way I've been able to get the distributor to drop in place. I feel like I'm off by one tooth and I've tried to compensate by turning the shaft a little further beyond the white mark but this too has resulted in failure. I'm about the throw up my hands and have it towed to a garage and pay $95 an hour to have it repaired. Since I'm retired and on a fixed income that's not something I want to do. Any suggestions?
@SchrodingersBox7 жыл бұрын
Keep trying there is no trick to it. Make sure you're TDC compression and set as I showed in instructions and it will eventually work.
@raybridges27387 жыл бұрын
Thanks for the encouragement. After taking a day away from the van I was able to get the distributor in correctly. It started up on the first turn. However, I still need to fix the overheating problem and C0265, P0300 and P0135. Yes, it's running but roughly. It's time to attend more of your classes. I'm begining to think an engine and transmission swap would have been easier.
@johnjones80215 жыл бұрын
I fixed my code p0305 , just by changing one injector , not the whole spider......it can be done....runs like a champ
@spiridondimaris4652 жыл бұрын
HI MATT I WAS. WATCHING THIS VIDEO PRINGME BACK IN THE GOOD OLD DAYS HOW YOU DOING MY FRIEND ALL WAYS YOU HAD GOOD VIDEOS
@SchrodingersBox2 жыл бұрын
Yeah my old videos were low video and audio quality but the content was good, I think!
@NewECus11 жыл бұрын
So i watched your video, and ive been trying to get my blazer fixed for almost a - cont
@maxwebster75725 жыл бұрын
My comment below refers to broken rings. In the case of a 2 stroke with reasonable compression , with triangular rings they are designed to seal on the power stroke not the compression stroke. Carbon is # killer.
@AnonMedic10 жыл бұрын
I don't take the fan off just upper shroud.... and I have a hard time turning the crank while trying to finger the spark plug hole.. So Pro-tip; take the shrader valve out of a compression gauge hose, and use a fuel line/vacuum gauge hooked up to it.. then you can visually see the HG/PSI as you turn the crank with both hands.
@goldeneagle87dy10 жыл бұрын
Thanks Helps a lot. I got a po300 code random mult. miss fire and I don't know much about engines. I hope I can find what's wrong in the summer. and I did replace all small stuff like spark plugs, wire, coil, rotor, cab.... and still nothing. so ill try the test's and see THANKS
@NewECus11 жыл бұрын
year now. Ive replaced the fuel pump, injector spider wiith the new mfi type, which included fuel pressure regulator, upper intake gaskets, spark plugs, wires, coil, distributor rotor (even tried a replacement distributor). I checked the timing as you described, and it checked out fine. Im still getting a misfire issue p0300.
@SchrodingersBox11 жыл бұрын
NewEcus, sorry to hear about the struggles you had however it sounds like a lot of parts have been changed without diagnosis which is exactly what my videos try to show to avoid. Therefore, for me to take a guess at what's going on is counterproductive to my efforts. Restart with the basic diagnostic procedures shown and the data will actually tell you what is wrong without having to guess. Feel free to post any data like fuel pressure, compression, vacuum, etc that you have and I can help.
@Mike_The_Hog_A_Nator Жыл бұрын
Mine was the Camshaft Position Sensor. Ran good but long start times & scan showed a misfire
@AnonMedic10 жыл бұрын
I take the fuel pump or ECU relay out when doing compression checks. Since it's under the hood.
@robertadams907811 жыл бұрын
Currently trying to fix my daughters 1997 Blazer w/4.3 EDI ignition. She had a cracked distributor, very common on the OEM Distributors I guess. Anyhow, I have followed your videos for installing the distributor, but with it being a replacement, I need to go to square one and find TDC. I felt I had done everything correct, went to fire it up and all it does is turn, does not fire up and run. I believe I may have hit TDC on the exhaust stroke, but that was as far as I could turn it.. CONTINUED..
@cody94198 жыл бұрын
I have a statement relating to something you will get into @ some point. There is thinking that the check engine light comes on when maintenanc intervals are reached. You disagree with this for reasons stated. In support of your position consider the following: There are models/makes of cars which have a light, separate from the check engine. It is titled Service Engine Soon. From what I quickly learned is that this button's function is to alert the user to bring in or service the auto for an oil change or something similar. This supports the idea that check engine lights are not used for the this purpose.
@SchrodingersBox8 жыл бұрын
+David Eichenlaub The SES, MIL, CEL are all the same. Service engine soon is indeed a DTC fault, not a maintenance light. Oil change indication will NOT be done through these lights- it will be done with a "maintenance required" or a specific "change oil" light.
@cody94198 жыл бұрын
+Schrodingers Box Okay, that's fine. it supports regardless. the fact that there is a "maint. req'd." or "change oil" light in the first place this means that these functions aren't achieved through a "check/service engine light". Agree?
@cody94198 жыл бұрын
A Check Engine light which is the result of a DTC. Diagnostic Trouble Code (?)
@SchrodingersBox8 жыл бұрын
+David Eichenlaub Exactly correct.
@mike131584 жыл бұрын
IAC is the abbreviation we use for the idle air control valve, many engines don't have a valve, some may have a Idle Actuator on the older throttle bodies or on some newer ones a AIS controller, not arguing do it what ever way you want, just saying throttle body and such get coked up and plugged up from EGR, so unless you've just cleaned it do yourself a favor and open the throttle. Don"t take my word for it, take one with a coked up throttle body and a plugged PVC valve or a faulty electric one, compare compression readings open and closed throttle
@eddieallen89828 жыл бұрын
now leave the fan off and tell your buddy to get a Concorde dual fan setup. electric fans are a time saver on future repairs involving the front of the motor.
@DESPYS1LOSTCITY Жыл бұрын
What was the issue?? Working on a Jimmy 1999..
@jerrypeal6534 жыл бұрын
I stuff a piece of plastic bag in the plug hole when it pops out I know I’m on compression stroke ,of course I don’t stuff it all the way in , just plug the hole .
@cavdrkz2411 жыл бұрын
So when the air pushes your finger away from the spark plug opening, that is TDC? Not sure I understand that part.
@exmerion7 жыл бұрын
I have a misfire problem that I'm currently working on with my 2000 blazer that gives me no codes and from the symptoms I've put together it seems to be a leaking poppet valve and old spark plugs. This misfire only happens when I've been running the system for a while and when it happens the engine boggs down when I try to accelerate too fast. When the engine starts it runs really strong in drive so there's extra fuel being dumped into the cylinders. Not only is the smell from the tailpipe rich but also from the front of the vehicle. This is a recent one but when I checked my oil it smelled like gas . So I opened up the throttle body and looked inside the upper inside and the areas around the air intakes where stating to wash clean. But now that I've watched this video I think I'll try your tests to see if my conclusion is wrong.
@SchrodingersBox7 жыл бұрын
Why not just do a fuel trim analysis to verify?
@exmerion7 жыл бұрын
I don't own a ODB2 scanner but I did order one which should arrive tomorrow which will allow me to use my phone to graph it. -I do have to admit though I was already leaning towards a new spider because it still uses the old CFI instead of the new mpfi system which was a recommended upgrade for my year. But you are right if I had done that and not looked at the fuel trims I would have been up shit creek- -Also I have no idea what exactly it would mean if my trims were calling for more or calling for less- Edit: sorry I'm not very smart. I looked it up and running really high negative would mean it's a fuel injection problem and running a high positive would mean it might be a pump problem or something else.
@exmerion7 жыл бұрын
After looking into it more I think I might go from OBD2 readings and if that shows I might have a leak then I can breath a sigh of relief and move onto fuel pressure and hopefully it only fails the leakdown test and not the maximum fuel pressure from pump I might have an easy day. The only thing I fear though is that it's a compound problem. I replaced the fuel component and still have a misfire so I have to do a manual cylinder balance test. If I find the cylinder and test the plugs and distributor and nothing is wrong with them..... I dread failing a compression test. because then ,from what I understand, nothing short of an overhaul could fix that.
@spelunkerd11 жыл бұрын
Yeah, I envy guys like Ericthecarguy who use wireless. I have a pocket hardwired, battery powered recorder, which is OK. But it uses a clumsy cigar-shaped connector which is awkward to conceal. I find myself getting lazy and just trying to speak into the camera mic, to avoid having to mix later. But sometimes I regret not putting in the effort, especially when there is no option for a second try.
@oisin1980 Жыл бұрын
I have exactly same engine . Mercruiser 4.3. Your videos are amazing. Question. 1 full revolution of flywheel can be compression stroke and another revolution could be exhaust???? So that has been my headache. Am i right???
@SchrodingersBox Жыл бұрын
Yes correct. 360 degrees crankshaft rotation is only 180 on camshaft. To cycle a full TDC compression cycle you need 720 degrees crankshaft rotation
@oisin1980 Жыл бұрын
That was such a helpful video. Your time to make it is much appreciated. Thank you.
@oisin1980 Жыл бұрын
I have changed all plugs etc. It's same chevy block in bayliner boats. I've replaced rotor and cap. I am getting massive misfires as loud as gunshots. The engine is pretty new. Wouldn't run after some parts replaced. I assume the bad timing would cause that. I have yet to see spark from plug disconnected and separate plug put in the end and grounded it. Can't see spark . This is all from cylinder 1 lead. I seem to have distributor set up as you have. Any thoughts?
@SchrodingersBox Жыл бұрын
Sounds like mis-timing to me.
@kimbeasley8910 жыл бұрын
I have a 2002 blazer 4.3L vortec. I aligned the timing marks like in this video and then aligned the distributor like you showed me in your other video and the truck would not start. I went back to tdc on the crank and then aligned the rotor with the #1 spark plug on the cap and it started just fine. Why is it like this? will not work on 6 or 8 marks but it will work when pointed to #1 spark plug wire on cap. thank you for your time.
@kimbeasley8910 жыл бұрын
I am also getting al little misfire between 1000 and 1500 rpm but it idles fine and if i go over 1500 it runs fine.
@SchrodingersBox10 жыл бұрын
kimbeasley89 To answer your second question, you likely have a vacuum leak if you have misfire at low RPM that improves with engine speed. For your first question, I'm not totally convinced you were at compression stroke TDC the first time- there are 2 timing marks on the crankshaft, make sure you "pass" the first one on the way to TDC and end up on the second one. But even so, that's weird, man.
@jerrypeal6534 жыл бұрын
Well Matt Going to get cold here on the front range hope your garage is heated .
@SchrodingersBox4 жыл бұрын
Yep I use a kerosene heater and garage is insulated. I’ll be cranking out videos this holiday season!!!
@garywiley737 жыл бұрын
great helpful videos
@98venom1410 жыл бұрын
In order to set to top dead center should you remove the distributor ? Chasing a miss fore and I think it was never installed correctly after a head gasket job
@SchrodingersBox10 жыл бұрын
I am not sure what you are asking... why would you want to remove the distributer before setting to TDC?
@98venom1410 жыл бұрын
Its a 4.3L In order for it to not turn along with the crank shaft...or can it stay in and once its top dead center pull it out and align the two pin wholes and redrop it
@SchrodingersBox10 жыл бұрын
Hernan Lopez I would leave it in and only remove and reinstall it if it shows to be out of time at TDC.
@98venom1410 жыл бұрын
Ok I will try it. As of now s10 just wont start it turns over and like sputters but wont stay on so hoping timing is just off Thank you
@uptowntrigor3 жыл бұрын
I hope this gets read. I bought a 99 2 door Blazer and after fixing it up it started running weak and just not feeling like it had the power it should. It also does a surge under load that moves the rpms a tiny bit. I replaced the spyder with the updated version and I checked vacuum. I replaced the O2 sensors and cat because they were bad regardless. EGR and PCV valves. Mass airflow. I check fuel pressure and it was where it should be ( slow leak if you let it sit for more then ten minutes primed ) But nothing I do helps the issue. My cousin ran a scanner while I drove and he said my timing was dropping from the 30s into the teens when the vehicle was doing its surging thing. I have put more time and money into the thing then I care to think about but I do love it. I just cant figure it out. I looked up cam and crank sensors but it has no issues starting or idleing. Any thoughts?
@SchrodingersBox3 жыл бұрын
yes you have a major clue when you said the O2 sensors AND cars were bad so you changed them. What data did you use to determine this? Also what data indicates the spider was bad? That’s critical data. And finally what was your mass airflow reading showing that you thought it was bad too?
@sikju2174 Жыл бұрын
Timing belt is loose
@jamesrobert78210 ай бұрын
Replace fuel pump
@geojor9 жыл бұрын
enjoy your vids...
@robertadams907811 жыл бұрын
Meaning that, when I crank the engine by hand, I hit a point where I can not physically turn it any further. Like it just hits a wall. Any ideas there? Because I am not getting the "obvious push of air" from the compression stroke that others speak of, I believe I am on the exhaust stroke, but why can't I continue to turn the crank? Is it a pressure build up issue in other cylinders? Do I need to remove other plugs to allow me to turn further?
@motorman17009 жыл бұрын
Great video! How is the best way to determine that a 4-cycle engine is on the compression stroke?
@SchrodingersBox9 жыл бұрын
When air blows out of the spark plug hole.
@normanabt73119 жыл бұрын
In
@smokeomatic6 жыл бұрын
Thanks for the great video collection of car diagnoses tips. Especially the one that explains fuel trims and how all the sensor input to the computer dictates how fuel is metered to make what 14.7 stoked sumpin. Great info and helped me understand how this all works. Has helped me with my 2003 4.3 Blazer as well as my mothers Subaru....hate that car. Just for myself and my cars can you recommend a good odb2 unit for not to much cash? One that will tell me all that data. Thanks again for the expert advice. Those who criticize are just jealous that they didn't make these to help others. Haters always gonna hate so fukem. Jay in Vancouver Wa
@SchrodingersBox6 жыл бұрын
Thanks for the comment. Yes my main go-to is the CRP Touch Pro from launch. but really for a beginner, any LIVE DATA capable tool will work.
@smokeomatic6 жыл бұрын
Live Data got it thanks
@davidmark42117 жыл бұрын
could you tell us what the other timing mark is for? also a video on how to adjust the valves on a vortec engine would be awesome. I love your approach to diagnostics. I read that all you do to the valves is set the timing to 55-65 degrees before the top dead center compression on one and tighten to 22 ft pounds is that correct.
@SchrodingersBox7 жыл бұрын
I believe the second timing mark (which is 90deg from the first one) is to line up with another tab on the cover, as opposed to the 0deg position on the timing indicator tab. Valve adjustment really doesn't require any skill on this model- just go in sequence to TDC at each cylinder so you know there is no tension on the rockers and torque per spec.
@davidmark42117 жыл бұрын
Schrodingers Box Thank you so much getting ready to start a head gasket job on one
@ateebeetee2jaytee9 жыл бұрын
When you spoke of the 2 lines on the harmonic balancer, which way are you turning the engine clockwise or counter clockwise.
@SchrodingersBox9 жыл бұрын
A Tana Always in the direction of normal travel- clockwise
@mike131584 жыл бұрын
compression test you want the throttle wide open fyi
@SchrodingersBox4 жыл бұрын
No need. more than enough air gets past the IAC and from PCV. The open throttle is a myth.
@mike131584 жыл бұрын
@@SchrodingersBox no not really a myth, I've seen many engines read 20 psi or more less if throttle plate is closed,especially smaller displacement engines, many engines don't have a idle air control valve specially a lot of newer engines like some drive by wire and what if your pvc is clogged and you don't know it yet, which happens, just saying with my 25 years experience its always good practice to open up the throttle plate so the engine can suck as much unrestricted air as it can for the most accurate compression test you can get, p.s love your stuff, I've always took a scientific approach, kinda like a car doctor
@SchrodingersBox4 жыл бұрын
Name one engine that does not have idle air control.
@Clearanceman27 жыл бұрын
Couldn't I find TDC by taking the cap off the distributor and lining up the arrow with the 6 cylinder mark and then verifying on the crank?
@SchrodingersBox7 жыл бұрын
Yes but that assumes the distributer was installed correctly. Virtually everyone does this wrong if they've installed a distributer on these models- hence my other video showing correct installation. While you're most likely OK using the distributer reference, I usually tend to be pretty specific on TDC being timed to actual piston and valve position rather than referenced indirectly- Usually because I normally get cars after some asshat has already tried messing with it lol.
@Clearanceman27 жыл бұрын
Schrodingers Box OK, one thing I should tell you though is you can turn the crank from the alternator bolt if the belt is on.
@mikehatley93938 жыл бұрын
ok Matt. I'm about done with ignorant people. this dude I work with brought in a 2012 Audi A5 with a apparent misfire. cylinder 3 was misfiring so guess what he did.?. And of course that did not fix the problem. he was sitting there scratching his head for about 45 minutes because he couldn't figure out why replacing the coil didn't fix it. so I go over remove the spark plug, i plug in my compression tester and lo and behold guess what, low compression cylinder 3. I hate Parts changers!! oh just letting you know those Audi coils are about $250 each.
@SchrodingersBox8 жыл бұрын
+Mike Haley, Yep if I ever see a misfire where the owner hasn't already replaced plugs, wires, and coil I would think it was a practical joke lol.
@2121bunny3 күн бұрын
Part 3?
@michaelmolter61803 жыл бұрын
That Autotap OBDII tool looks a lot more useful than noname Amazon scanner, but looking into buying one isn't promising---looks like it hasn't been supported in a while (Designed for Windows 98!). Do you have any current recommendations for something similar?
@SchrodingersBox3 жыл бұрын
yes they dropped support for it about 5 years ago or so- very unfortunate as the UI is the best in the world. I use Autoenginuity now.
@jeffreynobles9485 жыл бұрын
I am having a similar issue with #6 cylinder on my 2001 S-10 4.3L. I get a P0300 and also a P0306 when the vehicle is under load at around 3000 RPMs, and seeming when it is under load. I can have the vehicle parked and run the engine up to 3K RPMs and hold it there, and I don't get any misfires. By the way, I am using the Autoenginuity software for my testing. I am wondering if I have a compression issue on #6 cylinder. I have ordered a new compression tester, as my old one's gauge got busted from loaning it to someone....Grrrrrr! Anyway, all the other cylinders show no misfires in the history counters. I had a bad battery a couple of months ago, which I'm assuming would have cleared the prior history from that point. So, the history reported from that point back in February is 178 misfires on #6 cylinder since then. The truck runs good, and even when the SES light starts flashing, it still runs fine (I can't tell it is misfiring). Your video shows you checking the fuel system. However, I have replaced the spider injection system with the GM replacement injection system that incorporates individual fuel injectors for each cylinder. Therefore, it "should" eliminate any issues there with the crappy poppet valve design that GM employed back years ago. Would your next step in troubleshooting, as I stated, be to check the compression on the #6 cylinder and go from there? Thanks! Love your videos!!!!
@Skywindarmor3 жыл бұрын
I have a 2002 chevy s10 4.3 6cyl. I was having misfires under load and when going uphill. Switched tons of stuff and discovered that the 02 sensor wire was laying on the exhaust hose on the passenger side, it was also in contact with metal, which caused it to get some voltage, but not enough. I changed that out and my problem went away. Also another time when I was having a similar problem, it turned out to be map sensor and maf both going bad.
@silversurferhdz Жыл бұрын
How do i view part 2?
@deborahabercrombie9461 Жыл бұрын
if im pulling something off to cheack it im replacing it any part thats 20 years old needs to be replaced anyway
@SchrodingersBox Жыл бұрын
why? if it’s not defective why does it need to be replaced ?
@NewECus11 жыл бұрын
When i replaced the fuel spider, it ran fine, then one day on the hugh way i was accelerating hard then the engine died, i pulled over and stated again and it ran terrible, was missing alot, and its been like that since and i cant figure it out. Any ideas? The thing has 1987-- miles is it time to let her go??
@averyalexander23037 жыл бұрын
Matt, I have a bad ignition coil on my Civic 1.7. I physically do not have $15 for a junkyard coil, I have no job. It runs horrible on 3 cylinders. I unplugged the fuel injector on the dead cylinder. Will running it this way cause harm? Thanks.
@SchrodingersBox7 жыл бұрын
Yes it will cause harm. You're run raw fuel through the engine because of the no-spark misfire. This diultes the oil, damages the cylinder through friction and will destroy the cat very quickly.
@averyalexander23037 жыл бұрын
I unplugged the fuel injector on the dead cylinder as soon as the coil failed. Will I cause harm by running on 3 cylinders with the fuel injector unplugged until I can afford to replace the coil?
@sungchung13187 жыл бұрын
unburned fuel will also damage the cat
@PatchedRoundBall7 жыл бұрын
The first mark on balancer lines up underneath... Just an FYI. Good videos!
@SchrodingersBox7 жыл бұрын
You need to line up with the SECOND mark, not the first!
@shagdogfan59017 жыл бұрын
What about skipping with no check engine light? what would you recommend?
@SchrodingersBox7 жыл бұрын
Same procedure. You diagnose the cause of a problem, not the symptom of the problem..
@misterhandy51216 жыл бұрын
when you feel air pushing your finger is that TDC? or do you have to feel air and also move the harmonic balancer ? sorry i"m a rookie DIY'er .. Thank you!
@SchrodingersBox6 жыл бұрын
Feeling air pressure indicates you are on the compression stroke. It does not necessarily mean TDC.
@misterhandy51216 жыл бұрын
great just saw part 2 , so once i feel air pressure I can go ahead to the distributor to check the timing? sorry for so many questions and thank you again!!!
@SchrodingersBox6 жыл бұрын
Yes, after you have achieved TDC of course. Make sure you are at TDC before any adjustments.
@misterhandy51216 жыл бұрын
HOLY COW!!! I just saw that you have a subscription channel??? You better believe m signing up as we speak!!!! thanks for your knowledge and fast responses!!!you are the man!!! ok let me sign up now!! SCOTTY KILMER ," YOU ARE FIRED" LOL!!!!
@misterhandy51216 жыл бұрын
Just signed up...username ::MF2018 ......Thank You!!!
@marcosaviles541410 жыл бұрын
were is the second part ??
@gregrobinson98276 жыл бұрын
Hi Matt great video where did you get that clutch fan tool?
@SchrodingersBox6 жыл бұрын
I am pretty sure i got it from oreilley. The brand is lisle.
@chasehowell58679 жыл бұрын
this needs to be done before installing a new distributor ? Just want to make sure as I made a mistake I guess...I installed the distributor and the blazer is turning but not starting
@SchrodingersBox9 жыл бұрын
+Chase Howell see my video on how to install a distributer
@chasehowell58679 жыл бұрын
I believe I did. Set it on the #6 or lined it up really close after messing with the shaft in the motor you said to turn slowly until I get it positioned right. Previous problem though:took it to the mechanic here in town for a coolant leak. They replaced the lower manifold and head gaskets. Vehicle was running great when I turned it in. They told me I had did something and want another $977 to replace a distributer and a spider Vehicle struggles to accelerate before I removed the original neither of them had paint marks
@chasehowell58679 жыл бұрын
They had that pin lined up to neither the 6 or 8 when I removed it. It was pointing at the screw hole for the cap towards the back of the engine
@SchrodingersBox9 жыл бұрын
most common mistake is not being on the right TDC Mark for compression on #1
@chasehowell58679 жыл бұрын
+Schrodingers Box Think I found the problem. I'm removing the distributor now and redueing the TDC I found paint marks. 2 sets...1 orange one yellow (yellow being the second line) I didn't go far enough on the crank when I heard air. I'm in the process of doing that now. Thanks
@PawkaFlocka10 жыл бұрын
I'm chasing a misfire on my "98 Chevy 1500 5.7L Vortec. The only codes i've been able to get are P0171 and P0174 (I think) Lean on both banks. Also occasionally a catalyst code which im sure might be bad from all the unburned fuel going through it. The miss is on all cylinders under a load. whether it's in closed loop or not. I overtightened the dist cap on a previous repair (Similar symptom but not as severe. turned out to be cam sensor). and after discovering i had a 6 cast into my dist housing at the TDC #1 mark instead of an 8 I decided to order a new one since I knew I broke it. Do you think it's very likely the lean codes could possibly be caused by a misfire on all cylinders because the cap isn't secured properly? Thanks! As soon as I get the broken distributor replaced (With the help of another of your videos) I will continue my testing. Thanks!
@SchrodingersBox10 жыл бұрын
@Parker- I have to tell you that I would go after fuel pressure. lean on both banks and random miss under load.... Definitely fuel pressure test is what I would do if I were looking at it.
@PawkaFlocka10 жыл бұрын
Would you agree that it's more likely the fuel supply to the injectors versus the fuel supply from injectors? I did a injector balance test with a scan tool and at idle each injector seemed to effect idle exactly the same. I'll just have to wait until I get my distributor to get it up and running. Watching you're videos has got me really excited about diagnosing this issue properly! I am actually a service advisor at an auto shop and it's unfortunate that I have to admit my technicians are "parts changers" :(
@SchrodingersBox10 жыл бұрын
Parker Waite Parker, I do agree with you 100%. An insufficient fuel delivery would still allow for a negative fuel injector balance test result because the injectors would just be equally delivering insufficient fuel. I would go in the direction in this case of hypothesizing either a weak fuel pump or a dirty MAF sensor. I would look at my LTFT and O2s while driving the car and flooring the pedal. If the LTFT screams high and the O2 sensors go lean while it's floored, then it's 99% likely to be one of these two things. Then, following up with a fuel pressure test (if it's 55PSI or so while idling and it increases with throttle) then a dirty MAF is surely the cause and I would clean the MAF and retest. If the fuel pressure is low however, then that's surely the problem (and, possibly, there could ALSO be a dirty MAF to be really technical). But honestly the way you describe the symptoms, fuel pump or fuel delivery issue (bad filter, etc) is where I would bet you find the issue if I had to gamble on a guess- which I don't do. Incidentally, I have seen many Vortecs that have leaking fuel pressure regulators at the injector assembly- in fact I don't think I have seen one that doesn't have this to some degree. This must be a common issue on these engines, however this will cause a rich condition on these models because the regulator is internal so don't bother chasing that down even though many people may suggest that. Do let me know what you find.
@PawkaFlocka10 жыл бұрын
I certainly will. One other question regarding your video. In your flow of diagnosis once you determined it was going to be a fuel problem, you automatically ruled out the pressure regulator. Why is that? It may be obvious to someone who happens to be very familiar with how they work, which I am not. Haha
@SchrodingersBox10 жыл бұрын
Parker, great question and I don't think I clarified in the video why I dismissed the FPR (This video is over a year old and I dont want to watch it again lol) but to the best of my recollection there would be no reason to suspect the FPR. First, and most importantly, on a single cylinder misfire there is no reason to suspect anything would affect the entire engine which of course an FPR would. Second, I recall doing a fuel pressure test in this video and the pressure held steady. Indirectly, this also indicates a healthy FPR- had the fuel pressure gauge showed a drop at rest, a leaking FPR would be a candidate, but again not on a confirmed single cylinder consistent misfire so a leaking injector would be suspected at that cylinder. In this video I do find the fuel pressure to be low, and I cover that in the next series on low fuel pressure diagnosis and an FPR is certainly a consideration for low fuel pressure except you would expect a rich condition instead of the lean condition I find in the second video. And again, the fuel press gauge holds constant at rest in that video as well. The fuel pressure gauge is actually on the injector "spider" in vortec engines so if it leaks at all, it leaks fuel right into the intake causing a rich, not lean condition. If it leaks back into the fuel tank, then you would have a lean condition but again, the fuel pressure gauge would drop at rest, therefore, FPR not a factor in this vehicle any way you look at it.
@jasethebassuk7 жыл бұрын
Hi, I have a 1995 GMC Safari with a W code 4.3L engine. I'm having an issue with it in that once the van has warmed up after say 20 mins out on the road, it starts stalling when i slow down then after a few times firing it up again, it misfires and is very under powered. If I park up for around 10 minutes and fire it up again it runs perfectly again. I have cleaned the EGR valve and replaced the Coolant Temp Sensor. The van has also had a new IAC valve and new distributor cap, coil, rotor arm, ignition module and plug leads. The idle speed is generally fine but it also has periods where it surges sometimes, but not usually. I have a code reader and there are no faults showing. Any ideas would be appreciated. Thanks.
@SchrodingersBox7 жыл бұрын
Ok what data do you have that was leading you to change those parts? I would start there. Was there a low fuel trim caused by CTS? was there an ignition problem caused by the ignition module? I need to see the methodology- looks like just random parts swapping for no reason the way you are describing this.
@jasethebassuk7 жыл бұрын
Everything except the coolant temp sensor was changed by the previous owner. I've only owned it 10 days. He owned it 12 years. He claims it was stood since last October and wouldn't start, so he just changed the cap, rotor, coil, leads and module. It's so intermittent and I think he sold it unscrupulously because he was unable to trace the issue.
@SchrodingersBox7 жыл бұрын
Either way I need data to even have a starting point. There is nothing to go on here whatsoever.
@mrc60327 жыл бұрын
during compn test. where do you plug the guage in to test compression?
@SchrodingersBox7 жыл бұрын
the cylinder of course--- not sure what you are asking? Where else is there compression on an engine?
@mrc60327 жыл бұрын
Schrodingers Box ive never used a compression guage. so bare w/ me. just wondering how the guage is linked to the cylinder to run the test. is it plugged in where the spark plug goes? im learning mechanics. thats why im watching your channel
@SchrodingersBox7 жыл бұрын
Yes spark plug hole. You can also do a relative compression test as well connecting an oscilloscope to the B+ for the starter too.
@cody94198 жыл бұрын
Does anyone know anything about these OBDII connectors that bluetooth or USB to your phone or computer? I'm wondering how much I have to invest to get data like the autoenginuity used in Schrod's videos generates. Any thoughts?
@eddieallen89828 жыл бұрын
I've got the USB to obd2 cable from eBay ($10-20) and it's good for basic sensor data and reading codes. I also have a Bluetooth and wifi obd2 version ($10-20) but I cannot get them to work on my HTC phone or my acer tablet.
@johnsippel138710 жыл бұрын
awesome man
@amymcneal61807 жыл бұрын
You should say where it is before going into everything!!!!
@SchrodingersBox7 жыл бұрын
Where what is?
@Kamel4197 жыл бұрын
well, where is it?! :P
@teet35716 жыл бұрын
Amy Charbonneau WRONG
@fixitallagam98258 жыл бұрын
The film without sound
@SchrodingersBox8 жыл бұрын
The fool who doesn't know how to turn his volume up. You dumbass. Look at the hundreds of comments. And you think there is no sound. What an idiot.
@robingibson7503 Жыл бұрын
No sound.
@SchrodingersBox Жыл бұрын
Pretty sure it’s just you.
@Nono_7133 жыл бұрын
You save me 12,000 thanks I owe you lunch buddy at a cabaret
@Wgh4665 жыл бұрын
My missfire was timing cover seal
@SchrodingersBox5 жыл бұрын
How wopuld that cause a misfire? That has no effect on timing?
@Wgh4665 жыл бұрын
@@SchrodingersBox .after smoke test was coming from behind hamanick balanacer (cold engine) .drove for one hr and test againg becuase misfire allway go away after some time driving , i smoke it and no smoke leak . Also google, bad timing cover seal, symptom oil leak ,misfire ,rough idle . ( i google for a 2000 blazer )
@Wgh4665 жыл бұрын
@@SchrodingersBox some how there is a vacuum leak .and is bad .when i smoke it (cold engine) alot of smoke was coming out from behind harmonic balancer. Hot engine, no misfire and no smoke coming from anywhere. It did not make any sence. But Google confirm it.
@SchrodingersBox5 жыл бұрын
Ah- if the PCV system depends on the cover seal that would explain it. It would cause a vacuum leak. hard to imagine it could cause a vacuum leak enough to cause misfiring. What was your fuel trim before and after? That would be the prrof.
@powderb20097 жыл бұрын
man i wish you could put a magic touch on my truck, noone can seem to find and fix the problem
@SchrodingersBox7 жыл бұрын
It's not magic. It's science. Its the complete opposite of magic in fact!
@powderb20097 жыл бұрын
wish these mechanics could science then. They cannot find the cause of my p0300 random multiple misfire. Scanner shows misfiring cylinders 1 & 4 simutaniously between 2k and 2500 rpms. Only thing they found was timing at 14 degrees retarded, but claim distributor and timing chain are good. Im lost and love my truck but the lack of power it has is saddening.
@SchrodingersBox7 жыл бұрын
well if you happen to be in colorado i'd fix it for you. But there are literally a million things that could cause that. As with any misfire I apply my FASTTEC method and it will find it every single time. I have probably a dozen videos on this method.
@powderb20097 жыл бұрын
I'm going to change out my upper and lower intake gasket sets this weekend since i know it's leaking a little coolant on the ground and some into the oil. I'll try to adress other things I come across in the process. I'll watch all your vids in the mean time till I get to changing stuff out
@spelunkerd11 жыл бұрын
Boy, lots of videos since you signed on in December. I've sub'd, and I'll work my way through all your videos. You've got a problem with your audio, I can only hear out of the left side of my headset on two of the videos I've watched so far. Duane at Realfixesrealfast had the same problem, it's your vid camera. I predict you'll make enough from KZfaq to buy a new HD camera within a year -- I would do it now. Nice to meet you, Matt. Dave
@carloszepeda-reyes22334 жыл бұрын
Dude i need u to fix my suv
@Wgh4665 жыл бұрын
Any one that do backyard mechanic , u should allways have a smike machine
@MattDemery7 жыл бұрын
the audio is messed up here
@SchrodingersBox7 жыл бұрын
Old video in mono. Only right speaker works.
@SchrodingersBox7 жыл бұрын
Actually this is my first video ever lol. i remember this one hahaha. I didn't even have 1 subscriber yet !!
@MattDemery7 жыл бұрын
ROFL!!!! only my left speaker is plugged in. old amp that needs soldering badly. mystery solved!
@GlycerinZ7 жыл бұрын
I'm surprised you aren't already at 100K subscribers.. but I'm also surprised that ScannerDanner isn't, either.
@crapschamp99866 жыл бұрын
I had a cracked insulation on the coil wire put some electrical tape on it fixed i opened hood at night i saw it in the night kept running through coils 1997 4.3L v6 fuel pump just go in the fuel rail part to clean fuel in jectors with valve 60psi min lower than that wont start replace pump get rubber hose put number 1 piston top dead center dog wistel hose put hose in on1 cylinder when stop making noise it there turn crank buy hand ratchet have one person do it one listen stop when no no sound pop dristribter in number cilnder account gear turn when going in a hair before 1 cilnder computer will use crank cencer to set timing no marks to aline on crank for my year 1997 spark fuel
@SchrodingersBox6 жыл бұрын
I like turtles!!!
@skootb210 жыл бұрын
my miss is in #5 too lol
@Mikemeshell633 жыл бұрын
I never knew my blazer was kinky.
@cr1127844 жыл бұрын
My engine 🤓
@maxwebster75725 жыл бұрын
WASTE OF TIME! Car runs well on 5 so timing shouldn't be an issue but congrats anyway for checking it. Most car ecm's trigger fuel off of CMP sensor but that issue would set other codes. If your timing is off it will affect all 6. You checked spark which was fine but not under load so you don't know how many kV it's pushing which is a false positive. You checked comp which was also fine but doesn't rule out many other variables like sticking valve. Old school was to buy a GOOD vacuum gauge (not from Harbor Fright)[no E] and you can read it more accurately than all the above tests. You didn't verify broken rings on static vs running comp test or check the valves/ springs. A vacuum gauge is easy to hook up and you get more from it initially. A very commonly overlooked tool. Also had you some head gasket seepage the comp gauge won't show unmetered air. Fuel pressure test good call, also waste of time, we know it ran on 5. Yes the pressure is low, likely when you do the pump the change in vacuum will set an egr or iac code on top of your issues (and customer will get pissy and not pay) Easiest way to test an injector is with a stethoscope. if you hear the pintle move you have power/ ground. If you don't the injector is shorted or there is no power or the coil is open. That is wiring or component. Secondary to that you could have debris plugging it or buildup and it isn't spraying. Hook it up to a test bench, check spray pattern and turn upside down and reverse flush....or replace. Testing them on the car like that they can blow out of harness depending on style. In conclusion, vac test = don't get dirty. You know it's #5. Steth test she no clicky. Scope test would have shown it in the wave pattern easily but you guys don't like to pay diagnostics. Actually a lab scope has a vacuum gauge and you test the injector harness with the same tool or go buy an oscilloscope on Craig's list for $50. A noid light is very difficult to use on cars like Caddys with PCB intake gaskets that cost $600+. As far as diagnostics go, somebody brings in an old shitter like that and you will crack the plug boot, break a plug off, bust the dist. cap bolts and all kinds of stuff BEFORE you get to the actual problem. For the really tricky ones, you can use an amp probe to pick up the pulse on the injector on all sides of the plug before getting into plenum removal. You also can rewire those harnesses, it's very simple. Now, you also eluded to the fuel trim and we know that bank is running lean. Bad igntion will run rich. Sorry friend, YOU GOT LUCKY AND ACTUALLY FIXED IT.
@SchrodingersBox5 жыл бұрын
Your lack of competence is overwhelming. Its obvious you have no idea what happened here. Vacuum gauge HAHAHAHAHAHAHAHAHA!!!!!! ROTFLMAO!!!!!
@maxwebster75725 жыл бұрын
@@SchrodingersBox That is exactly the response I would have expected from you.
@SchrodingersBox5 жыл бұрын
@@maxwebster7572 Which means you must watch a lot of my videos.... ironic. You'd think you'd have learned the basics by now but you haven't.
@maxwebster75725 жыл бұрын
@@SchrodingersBox I have never previously watched any of your videos. I don't think I'd care to watch any others. I expected you to have a smart ass comment rather than LEARN something worthwhile. If you want to say something smart then research it and prove my ignorance, I have thick skin, I can take it in the light of bettering my capabilities.
@SchrodingersBox5 жыл бұрын
@@maxwebster7572 Then in that case, you would be stupid. I can't help stupid. Good luck.
@debdodson98676 жыл бұрын
In reply to the diy video diagnose no start due to no spark...Yep...I'm a princess you cowardess bitches..Thanks for posting the marks on the harmonic balancer to install the distributor;helpful on an intake gasket replacement...I hope that's a lemon job that's prevalent in the engineering of the wiring harness on those makes and models and I get lucky..
@GhettoRanger018 жыл бұрын
The word is "methodical" NOT "methodilogical" when in doubt check it out.
@SchrodingersBox8 жыл бұрын
+GhettoRanger Maybe you should check it out because the words are independent and NOT synonyms. Methodical refers to following a structured established logical process. Methodological refers to DEVELOPING such a progress in an adaptive sense. The latter is the approach I use, not the former. Please do your research next time- there are hundreds of thousands of people who see these comments and you don't want to look foolish.
@GhettoRanger018 жыл бұрын
Methodical definition; performed, disposed, or acting in a systematic, orderly, way. I didn't mean to be critical so don't take it the wrong way. I thought your video was excellent, very informative. I have a misfire on #5 4.3 vortec, it had water in the gas tank. I drained and cleaned the tank, replaced fuel pump and filter after draining the fuel line, I'm hoping it will start to work normally after driving for a while. PS Methodological will work you were not incorrect.
@SchrodingersBox8 жыл бұрын
GhettoRanger Yes of course I was not incorrect. YOU were. So of course I do not take offense. Again, when in doubt check it out. The words are not synonymous. You didn't even realize there were two words.
@GhettoRanger018 жыл бұрын
Actually either word would work.
@SchrodingersBox8 жыл бұрын
GhettoRanger Once again incorrect. WHEN IN DOUBT CHECK IT OUT. I focus on methodological, not methodical approach. Either way your initial post was "it is methodical, NOT methodological". Now you're saying both would work.. once again- check it out first next time so you stay consistent.
@grangerrussojr20448 жыл бұрын
wassup
@SchrodingersBox8 жыл бұрын
+chicos gang nsw sk chicken butt.
@Mik3yLow6 жыл бұрын
So you show us what's wrong with his, what steps you take, and nothing else? If my problem is a compression issue than this video is absolutely useless.
@SchrodingersBox6 жыл бұрын
TThere is nothing else to show- anything else is just basic bitch bolt turning. I don't need to show people how to spin a bolt do I? If the problem is compression related then this video shows EXACTLY how to diagnose that, so how would it be useless?
@gobloit447310 жыл бұрын
Saving money??? HA HA HA!!!!! Yeah buy a laptop and software!!!!!!
@DENicholsAutoBravado10 жыл бұрын
If you already have the laptop it's not that bad. I already have an android phone so I got a $30 amazon tool that uses my phone as the processor rather than buying an expensive scan tool that needs it's own processor. I was careful to buy one with good reviews. Got torque app professional and $35 later, I'm saving money repairing my cars right and making money fixing my buddies cars with fewer parts thrown at it. I say fewer, and that's usually true, but one of my buddies car was so far behind on maintenance that we had to throw a lot of parts at it, diagnostically they were ALL bad, before we could one at a time fix 5 actual parts that were bad. Amazing that car was still going down the road, lol.
@SchrodingersBox10 жыл бұрын
DE Nichols Its not bad even you don't have a laptop. I get a lot of comments from people like this guy who just plain failed basic math in 3rd grade. At $400 for the device and maybe a $200 used laptop the investment will almost pay for itself the very first time you diagnose a repair with it seeing as most repairs nowadays are over $500 and the next repair you use it for it will absolutely pay for itself and then some. But then again, a person who can't do basic math likely won't succeed at diagnosis with a scan tool so maybe this guy is better off just going to a shop.
@DENicholsAutoBravado10 жыл бұрын
Your final conclusion is the conclusion that I came to me as I watched more of your videos. I'm now watching your videos consecutively from the oldest forward. I can watch five of your videos to one of Scanner Danner's. It's how you talk. You talk at the camera. Thank you for your process that I can absorb so much better. You think ahead on how you present information. If I was in his classroom I'd fine because I could see him.
@SchrodingersBox10 жыл бұрын
Man, thanks DE!! That's a huge compliment and I really appreciate all your support on the channel. You are a huge contributor and people like you who "get it" are the exact reason I made the channel. Indeed I do a lot of prep work on these videos to ensure they are inclusive as possible. It's nice to see the effort is noticed!!
@daviddoniassr.28516 жыл бұрын
Man he talks too much!! Get to the point!
@SchrodingersBox6 жыл бұрын
I usually get this from basic bitches who don't understand the material. What is YOUR method of diagnosing this that is better than my method?