Cranking No Start -Quick Basic Diagnosis

DIYer doing a rapid diagnostic for a cranking no start on a 1996 Geo Metro using basically just a testlight.
You can see the cause of the fault in this video on my pay channel at www.schrodingersboxqm..com!!
Other Relevant videos to watch:
FASSTEC No Start Diagnosis: • No Start Diagnosis FAS...
For more in depth training on the methods used in this video, visit my other channel Schrodinger's Box Quantum Mekanix:
/ @schrodingersboxquantu...
Other no start videos:
• DIY- How to Diagnose a...
• Cranking No-Start Real...

[@carobama]

My 93 Metro quit on me as I was driving. Came across this vid and decided to check the fuse FOR A 2ND TIME, this time I took it out for a better visual and Thank You Very Much, sir. I knew it was fixed when I heard the fuel pump priming. There was a short in my system that I was able to fix too. Great video.

[@spelunkerd]

Very well done, Matt. I agree with those who like to see minimalist equipment used, simulating what we might have at the roadside. A similar situation happened to me hundreds of miles from home, and with my family aboard I quickly asked for help from the mechanic in the shop 50 feet away. It took him over an hour to find a blown fuel pump fuse, and to my surprise he only charged me $20 for his time. I think he was feeling a little sheepish he didn't find it sooner. As you say it's not at the top of the list, and other data like the absent spark can send the investigation down the wrong rabbit hole.

[@SchrodingersBox]

Yeah there is no shame in taking hours to find an electrical problem- even days to find one that's intermittent. Good for that mechanic. But still doesn't explain WHY the fuse blew as you well know.

[@cassiechavarria1167]

I have just started to DYI on my van and I found your website. I thank you for you taking the time to explain things.

[@snmdws2759]

Man, I've watched a lot of your videos because you are knowledgeable and have a quick way of getting to the problems. I have picked up a few short cuts from you and I appreciate the time and effort you put into these. That being said, those geo metros are awesome. Don't knock em til you try em! Geo for life....

[@SchrodingersBox]

Lol- it's not just you- I have come to find out there is a considerable following for these little Metro's. I don't get it... but I can't deny it lol! You are certainly amidst a lot of company!

[@snmdws2759]

Schrodingers Box , they are great for commutes or cross country trips. The gas savings for the 93 convertible LSI I had paid for the car. I had it for 100,000 miles and all I did was oil changes and brakes. Maybe grind out the dents from all the vagina rubbing on it every now and then but still worth it. I hope you keep making these videos, the banter in the comments alone is worth the time.

[@michellet_thatsme]

@@snmdws2759 😂👉😹👈 Dude my best friend drove one of those back when we were in high school in 2007 and man it took us on some of our wildest adventures. I miss that thing honestly.

[@8953147]

I'm glad your back Matt ; keep the videos coming for us 2%ers!!

[@cw2lido]

I'll never tell another mechanic what to do first, I'm all about learning and it's good to see you're back in the Tube!

[@SchrodingersBox]

Exactly. Unless there is only ONE variable, what you do first is scientifically irrelevant. If however there is only one variable and the mechanic takes an unrelated action, well then he is an idiot.

[@InternetDude]

Nice! One of my all time fave KZbinrs!!! So much better than the mainstream mechanic channels.

[@viscounttrimingham1862]

Yes, glad to see another video, you're an inspiration to a hopeless amateur, many thanks and keep them coming.

[@johnobiro5202]

You are absolutely brilliant. I love your knowledge and the way you interpret it. Give me more.

[@hassanal-herbi8439]

very very clear discription for the not starting problem. thank you

[@owoichoacheme2241]

You are really my good mentor when its come to diagnosis. Thumbs up man.

[@johnnyz9927]

Thank Shrondingers Box.....Hopefully soon I can get this Kia Spectra started so I can get to work.Then I can purchase the premium ch. Thank , you have always been informative and I appreciate you..

[@jadosmart1298]

you explain a lot in your videos. they are really helping me. makes me want to add mechanic to my carrier as a part time job. i love troubleshooting.

[@siucbset]

Back: Glad to see you again. I always like the overwhelming majority of your videos.

[@georgevalencia1713]

Finally! Someone with a real brain.

[@richard1835]

I am glad you are teaching again. I learn alot from you. Keep up the good work.

[@flightmaster178]

Thank you Matt for another awesome video! I love the FASTTEC method. Keep up the great work!

[@SchrodingersBox]

Yep it works EVERY time. It is scientifically impossible for it not to work.

[@jameswest9802]

Thanks for the videos! I've watched, learned and applied quite a bit especially with my daughter's 2002 Malibu. At the very least I've saved hundreds in diagnostic fees! I'll check out you other channel; I'm sure it's worth it.

[@NinjaKittyBonks]

Sound diagnostic skills right there. Well done!

[@whitetiger8652]

Glad to see another new video Matt! Thanks

[@ElegantElliott]

My car cracks slower than that. Any ideas? 5.7 hemi Chrysler 300c

[@lastname4321]

Elegant Elliott change your batrrey bro. .

[@kirkbrown2147]

Either than batter check voltage drop on the starter circuit

[@chrismooremusic4383]

Change your starter and battery

[@bigfred1696]

Love your channel. I have to admit most of your videos are over my head, but trying to learn...thanks man

[@SchrodingersBox]

My other channel is ideal for you then. You should definitely check it out!

[@thecardoc100]

A few notes. Avoid probing the female pins in a connector or a fuse block with just a test light or voltmeter probe. It's OK to touch the terminals but don't jam the probe into the pin because that can cause terminal tension issues. As far as when is the right time to check the fuses, the right answer is after you have a sense of direction such as whether you were missing fuel, (pump operation and/or injector pulse) spark or both then you can start to drill down to "why" those were missing. Otherwise any other test choices made would be totally random in nature and could just as easily be wrong or right on any given vehicle.

[@SchrodingersBox]

Great advice for sure!

[@movingupautodiagnostics8645]

You're back! Man I missed you!

[@SchrodingersBox]

Good to see you too man!

[@alfredohernandez1124]

Help

[@jimmydiaz7781]

h LLP p0

[@phantom21629]

Love you videos. You couldn't be any more correct in your process. I always check the fuses first only because in my profession I always have a volt meter handy and I'm usually on the side of the road and its the only hope of fixing it right away being that I will have extra fuses in the glove box. Randomly checking fuses is just stabbing in the dark.

[@eastloscalifas4568]

thank you for sharing some knowledge with us..

[@shaunsautorepairs5410]

Welcome back matt.. A long awaited video...12 minutes to watch the vid and 45 minutes to read all the comments. Love the humour Keep up the good work

[@SchrodingersBox]

Yeah some of my vids are like Yahoo! News articles..... The comments are better than the actual publication lol

[@itubeutubewealltube1]

​@@SchrodingersBox hi , I have a metro too, I just drove through a puddle , it was raining. Did something for an hour , came out, the car started , drove home. Next day the car wont start. All the lights and electical works when I turn the key. Sounds like fuel pump is working. But no "click" and nothing from the starter. Not turning over. I was wondering if the water could of gotten on the starter and caused this problem?

[@pamelavance648]

Watch listen learn and read yep 😊😊😊😊😊

[@shaunsautorepairs5410]

Matt... did you just hit the love button for my comment.... it only took you 6yrs...haha

[@SchrodingersBox]

Hahahahahahaha yeah I was actually doing that for a more recent response but then I thought what the hell- I love that old comment too hahahahaha

[@butchbiker9179]

Imy Geo metro was doing the same. Yes it was the fuse he replaced in this video. thanks!

[@Pablo_Automotive]

Great job Matt, the FASTEC is a good sistem of diagnostic. Regards from Spain.

[@SchrodingersBox]

Hi Pablo! Good to see you my friend!

[@InsideOfMyOwnMind]

I bought the predecessor to this new in 1984. It was the Chevy Sprint by Suzuki. It got 60mpg hwy with a carburetor.

[@newlife3990]

Great tutorial, well done.

[@garypowell4565]

Good job! I'm learning stuff here, because the usual way I approach problems is with a WAG (Wild Ass Guess), and usually just start replacing shit. Thanks for all this valuable knowledge.

[@SchrodingersBox]

Hahaha "WAG"- I am going to have to borrow that one from you lol!!

[@henryszweblik3626]

thank you for sharing some knowledge with us.

[@alcyr5655]

Just a new sub., who has watched a lot of your diagnostic videos on crank, no start. A lot of it is way above my head, couldn't even catch it with a ball glove. FASSTEC is very helpful. Still working on getting my sons car running. I just don't want to throw random parts at it. Even worse, it's on my sisters sloped driveway, wind is from the north, and snow. Wishing you and your loved ones a Merry Christmas, and a Happy New Year.

[@SchrodingersBox]

Thanks for dropping by. The more you watch of these, especially my "Diagnosis and Understanding" series, the more you will understand this stuff!

[@alcyr5655]

Just finished watching your HOW NOT TO FRY YOUR PCM video. That was like gold to me. I've been working on my sons 93 Grand Prix for over a week, after work. Their is so much bad information on youtube, and google. So as a 50 year old man, who prefers older trucks/ I have a'80 Powerwagon 360, 4 bbl, 4 spd, a '57 Dodge 1/2 ton with a '69 Plymouth front clip welded in, for IFS. Daily driver is a '99 Ram 1500. I grew up with the saying, if you cant fix it with a hammer, you have an electrical problem. Computers are like voodoo to me, scared to fry PCM. Learned a lot by just watching your videos, Fawk tomorrow is going to be -20*C with a wind. Just wanted to say thank you, for sharing your knowledge. The 40 thumbs down are probably from people who cant figure out how to get their bicycle chain back on. Season Greetings from Alberta Canada.

[@marleythechameleonandherbi2724]

Good to see you back Matt. Looks like you may be gathering some new material for addressing the "hate mail" again!

[@SchrodingersBox]

Hahaha already got my list! Just need time to put it together! I got some really good ones!!

[@ampload]

Ok I will try that... Thank you so much Matt ... your the Best !!! I appreciate your help alot my friend .

[@JasbirSingh-zj1fg]

Great job diagnosing the 3 cylinder Geo Metro. Of course one never knows ahead of time where the problem might lie but only the smart guys who know what they are doing find the problem as fast as you did. So once again, this was great. My 8 cylinder VW Touareg also has been acting up. It has this weird gas-mileage problem and no mechanics have been able to diagnose it because the Touareg behaves good when it is at the shop. The problem with the truck is that during my commutes to work, most of the time it gives me poor gas mileage (15.5 - 16.5mpg average), but sometimes (~15% of the time) gives me very good gas-mileage (18 - 19 mpg average). Usually (but not always) the good gas mileage is accompanied by more power and slightly better sounding engine. At first I thought it probably had something to do with engine-temperature or humidity etc, but after many weeks of observing I have to say that neither engine temperature, nor humidity, or traffic conditions, or AC on/off, have anything to do with it. It seems it simply has to do with what mood the truck is in. When the engine feels powerful, I drive it slightly more aggressively and still end up with the same great gas mileage. Needless to say, I want great gas mileage accompanied by more power, all the time. Have you ever come across such an issue? Where do you think the problem might lie? I have some basic scanners but being a novice, I need guidance as to what I should observe and what I should look for. TIA

[@SchrodingersBox]

WHat data do you have?

[@JasbirSingh-zj1fg]

I am new to engine diagnosis so I don't much know about which data to watch. However, after watching your videos on Fuel Trim a few days ago, I watched mine and what I saw is- 1) When the engine is fully warm, the multiplicative LTFT stabilizes at around 4% on both banks, but does not always stay there. Sometimes bank 1 rises to 5.5% (and stabilizes there) and bank 2 rises only to 4.7%. Occasionally bank1 rises to 6.6% and bank2 to over 5% and stabilizes there. However, most of the time it is around 4%. The additive LTFT is almost always around -1%. 2) The Lambda for all 4 sensors is almost always at 1.00. Upon deceleration, two of the sensors rise to 1.99 but the other two remain around 1.00. I'm not sure if this is normal. 3) The only thing that may be odd is the voltage for rear o2 sensors. It rises to over 0.6v when cruising or when engine has been idling for a while. Doesn' t that indicate a rich condition? I have brand new front catalytic converters. Shouldn't the rear o2 sensors always be around 0.45v? I have not been able to figure out where to find the voltages for front (pre-cat) o2 sensors. There are some values that show voltages of around 1.55v (on both banks) when cruising which rise as high as 4.2v when decelerating. I suspect that those are the front o2 sensors but I don't know why the voltage range is so different from the normal (0.1v- 0.9v) o2 voltages. What else should I watch?

[@konyoha]

good basic diagnosis..Thank you from Indonesia..

[@davidh7636]

Enjoyed video. Nice to see the steps you take for diagnosing the no start condition. I never knew that if the fuel pump doesn't work, the computer shuts of the ignition. Not like the old days. That can get confusing. No fuel equals no ignition. Weird. Thanks for the video. Good to see someone that knows what they are doing working on cars.

[@SchrodingersBox]

Yeah it's not so much that the PCM shuts down the ignition- it's more that the secondary shares the same circuit so when the fuse blew, both fuel and spark were affected. But indeed sometimes the PCM can independently control a cylinder. For example on some models a misfire in a cylinder may result in PCM shutting down that injector intentionally to prevent washdown and cat contamination.

[@davidh7636]

Thank you. Good to know.

[@paulalferez4339]

Much better video presentation. Stayed on da subject thru da whole subject.👍

[@942doc1]

Awesome, came here to diagnose a no start camry. Got a solid clue of where I got to be.. (I remember watching your vids awhile back) definitely knew this guy knows what he's talking about 👌

[@SchrodingersBox]

Hope you solve it!!!

[@942doc1]

@@SchrodingersBox yep, did too. it was a blown fuse that supplied 12v to the ignition coils. I think I blew it when I tried jumping the starter to check compression after I rebuilt the motor..

[@FASTECAUTO]

Hey boss you really inspire me!

[@alazanjoe]

very informative and thorough, thank you

[@jaimegenovajr3257]

I really learned a lot on your videos brother

[@SchrodingersBox]

Glad to hear it!! Thanks for watching!

[@1968hambone]

Very well done man!

[@bnewton239]

that was quick, a pleasure to watch.

[@tiitsaul9036]

good to see you again

[@SchrodingersBox]

Hey Tilt, good to see you too!!

[@whoisharo4689]

Love the name of this channel. Very clever 🐱🐈

[@SchrodingersBox]

Thank you! 😊

[@rrmech11]

hello matt nice to see you back

[@SchrodingersBox]

Good to see you too!

[@labradormcgraw]

Just watched the second installment of this repair on the pay channel. Honestly, Matt, you deserve a medal just for getting within fifty feet of that rancid mobile garbage bin. How can anyone not be embarrassed to bring something like that in for repair? It takes all sorts, I guess.

[@SchrodingersBox]

Hahahaha. Man dude you don’t know the half of it. So I don’t want to piss the guy off because he is a very good friend and he is a regular who brings me a lot of business but this was one of his nicer cars hahaha. You should see his work truck. OMG it’s..... You can’t even imagine. The dashboard is missing, the doors are wired shut, the lights were wired in through a residential light switch and once when trying to get the defroster to work a huge mouse nest fell right on my face when I removed the air duct. He was also the owner of at least 5 cars shown on this channel- the Suzuki esteem where the subframe rusted out, the “420 code” video where the car smelled so much like weed I was getting a contact buzz, and some very early videos where I did shocks and brakes.

[@labradormcgraw]

@@SchrodingersBox Wow, how do people let their vehicles get into such bad condition? I remember the car with the weed problem - I don't know how you got within a mile of that one either! And as for that mouse nest... words fail me.

[@thatsdaniellelol]

This was actually really helpful as a Crank No Start refresher.. Thank You!!

[@bakaniemlalazie4458]

l got a Nissan elgrand can't start no spark pliz help

[@wyattoneable]

Pretty cool stuff, thanks.

[@mthqwork123]

It's always good to watch your vids. Easy to understand even if English isnt my 1st lang. :)

[@SchrodingersBox]

Thanks!! I get many, many comments that my use of good, proper english actually helps people very much who have English as a secondary language. Good communication is the first step to good understanding!

[@mrAq_pA]

isten hozott :)

[@surendrajugdave9295]

good job . all ways for your uploads .

[@jonsdiagnostic5879]

Miss you man!

[@todayintheshopbanksy5904]

I hadn't realised you were back to regular postings on the pay channel, I unsubbed when the videos dried up after your promotion. It's really good value, when you consider what you get for your money. Less than the cost of a Pint of Beer over here in the UK. You guys really should give it a watch. And no Matt isn't paying me to say this.

[@labradormcgraw2409]

This guy is brilliant... Absolutely brilliant.

[@SchrodingersBox]

Lol you gotta stop binge-watching or you'll go blind my friend!!!!

[@webslinger2011]

Nice to see you again Matt. Scope pattern might reveal something about the fuel pump. I still look forward to your videos although I shifted to working on electric motors.

[@SchrodingersBox]

Yes I was indeed suspecting the pump and tested it but using other methods since most viewers don't have a scope.

[@douglasgreen437]

👍 Great work....

[@wallykaspars9700]

I had the crank but no start problem with my 1998 Ford Escort. The problem was a worn ignition key. I used the original key which was seldom used and the car fired up with no problems. After 16 years of using the key made at a hardware store, it was a bit worn on the edges.

[@finwardscott144]

Good job.

[@rockt73]

what a treat a video from the cat!

[@jethrodgonong2254]

Nice one sir!

[@buddyboy1953]

Great video thanks !!!

[@djmalue1]

Great vid man. Ur on point sir!!!!

[@olasdsd6538]

Hey Matt, thank you for the great video! Why is there 1 Volt even though the fuse broke?

[@SchrodingersBox]

It is because the circuit is shared with other circuits and we are just seeing some background.

[@cristobalvillalpando7451]

Great video, very helpful thank you

[@SchrodingersBox]

Glad you enjoyed it!

[@shaggard12]

something you might concider is to use a 12v automotive circuitbreaker inplace of a fuse. breakers come in different amp load sizes. its been my experience that blowing fuses until the problem is found is not only likely but can be a frustrating when you have too continue changing onetime use fuses. it seems to work well for me. like your show and your methods approch the challenges well.

[@SchrodingersBox]

Why would you blow fuses until the problem is found? Once you identify the problem circuit there is no need to put another fuse in it until you locate the short first.

[@aussiebloke609]

Woot - the cat's back! Good to see you have a new video, Matt. :-)

[@aussiebloke609]

PS: I'd guess at this point there's a possibility of either a chafed wire somewhere in the fuel pump circuit, or maybe even a pump that's on the way out and pulling a bunch more amps than it should...but not entirely sure why that would have prevented you from getting spark. Are those systems usually interconnected? On the other hand, I AM sitting here in my armchair...and that's why I don't know. :-)

[@SchrodingersBox]

Yes I would suspect the fuel pump first however the ignition is also on the circuit obviously so it is entirely possible the ignition circuit is also the suspect. ANything- fuel injector, coil, fuel pump, and all associated wiring is suspect at this particular point. I will narrow down to what it is exactly hopefully tomorrow.

[@johnfountain8143]

Im sure you have thought of this but might be worth measuring the current flow at the fuse , with a slow build of current a 15 amp fuse will carry 20 amps or more for quite some time before it blows Best Regards John

[@nen.user.3764]

Anther great video. Narrow that diag down to where in the fuse box first. Always look for obvious visible signs of things. And basic functionality tests.

[@8683roy]

Matt could you please elaborate about the fuel & ignition being on the same circuit? I've always thought they were separate circuits & when you pulled the fuse it only said "FI". Are they always together or just on certain models? Is there typically no ignition fuse then or does that vary between models?

[@SchrodingersBox]

Just certain models. On my other channel we cover the wiring diagram for this model in searching potentials for the short circuit and I can tell there are other things besides fuel and ignition on it!! It's one busy circuit (which makes tracking a short much harder of course!)

[@abdonrodriguez3586]

Thank you!

[@vikasmotortech80]

hey!! maat sir.. how are u. Every time you explain something thank you sir

[@SchrodingersBox]

Hi Vikas. Good to see you again!

[@scottrose5012]

That was a great video, thank you for sharing. I am having problems with the same type of Geo this video covered which I would like your opinion on if possible or find out if you have already covered the problem in prior videos you have made. The 97 Geo I have will start twice then just crank over and not start again until I have disconnected the battery and let it set over night then the same thing will happen again. It will start fine and run fine on the first start, second start the same, third start all the check engine lights come on and it will just crank over with no start. I just don't understand on electrical end of things how you trouble shoot to find out if it is a sensor or part has gone bad. Does this sound like it could be a cam or crank sensor problem?? Any help you could offer would truly be appreciated, thank you...

[@SchrodingersBox]

I would try a cam and crank sensor bypass test as first step.

[@scottrose5012]

@@SchrodingersBox Thank you, I'll try that and see if it makes a difference.

[@baddriversofnorthtexas6850]

Ill be towards colorado springs in a month, cant wait. A high of 80 degrees there vs 105 here.

[@SchrodingersBox]

Yeah the springs is usually a good 10-15 degrees cooler than Denver. I have been working in Phoenix a lot this summer. It's been brutal!!! Last trip was 122.

[@baddriversofnorthtexas6850]

Schrodingers Box I wonder how much HP is lost up there because of elevation, and what percentage of people have thrown on turbos to make up for it.

[@Eurospec73]

Great video man. I have a crank no start on my 2.8 liter VR6 the motor was just freshly rebuilt and I believe I'm getting no spark. I checked all fuses and they are all good, the ECM relay is good as well. What could be causing this crank no start/ spark issue? What a ground wire missing from the transmission to the chassis cause this?

[@SchrodingersBox]

right now you have to first determine the missing FASTEC component. once you do then you will be able to pursue variables. if you find the coils are not firing AND they are internal transistor design then yes a bad ground is possible. otherwise it is not possible since each coil would be ground side switched.

[@Eurospec73]

@@SchrodingersBox 🧐🤔 I see what you mean. I'm not quite familiar with the term "FASTEC component" but I think you're referring to a missing electrical wiring component? Is that what you mean? In a nutshell from my understanding the ECU relies on several ground points throughout the engine and some on the transmission to crank and start and run properly. I definitely think I'm missing a ground wire from my transmission to the chassis as I just found a photo I took out the car last year and it was on there. I'm going to go and try to reconnect it, and hopefully the car will start 🙏✝️ thanks again for your support on this. I'll keep you posted.

[@InternetDude]

I have an O2 sensor diagnostic video I uploaded recently. I show what to do to diagnose without a scan tool (pre-OBDII) and without pulling out the parts shot gun.

[@kennethkristensen5537]

Tip to identify the coil on the relay, use an ohm meter. The contact set will show either 0 ohm or OL

[@janmartinmathiassen6265]

Hah, I just had a fuelpump die on me a few weeks ago, and the first thing I did was try to hear the fuelpump, then the fuse, then leave the ignition on and beat on the tank (which apparently kickstarted the fuelpump). Drove it to a shop, switched the ignition off, tried to start it again, same problem. Told them to swap the fuel pump, and voila. Not quite the 2% method, but I'll take it. But I agree on the fuse thing not being the obvious thing to check first, I mainly did it because I didn't have any tools with me (nor am I really that proficient with electric diagnostics etc, but I love watching others do it :P), and it was an easy thing to check. I would've been very suspicious if my car had had a blown fuse though, so will you be providing an update on this car if it happens again, and/or if the actual reason behind the blown fuse is discovered?

[@SchrodingersBox]

Yes i show on my other channel why the fuse blew and the repair. You can check tbout for free.

[@chrised1115]

love the video..just wish I could see the end result of what's happening to blow that fuse without paying to watch it on your other channel.

[@SchrodingersBox]

Well it depends on how bad you want to see the final fix. If it's not worth the money then it's no big deal. If you can't live not seeing the final repair then of course, the value is justified. Only you can decide that.

[@chrised1115]

Schrodingers Box I understand, I will honestly probably wind up doing it because I don't like cliff hangers! thank you for your content and reply

[@ampload]

Hey Matt Some Good News !! I Directly Connected 12 Volts DC to the Fuel Pump and heard the Fuel Pump spinning and have good fuel pressure to the fuel filter also. But am not getting 12 DC ( Electricity ) to the Pump ...and no spark?

[@SchrodingersBox]

Perfect!! I would do a bypass test on the CKPS as next step to verify spark signal.

[@src4409]

Just feeling the need to pop in and tell people that the basics don't always diagnose every crank, no start issue.... especially with vehicles later than 03 at least. Cat issues became a really big problem in the mid 2000s. Just got my 08 started after pulling an o2 sensor and spraying seafoam into the cat. And then I torched the sensor end of my o2 sensor to burn off the build up....red hot. Car fired up and ran for quite awhile. Will probably have to replace the cat and the o2 sensors shortly, but this was a quick fix until I can get the parts ordered. I had zero codes at all. Once I got it running I had a cat/o2 code that was there months ago and went away. Hope this helps people who have tried everything with no prevail.

[@SchrodingersBox]

that’s makes no sense. none of that would cause a no start. absolutely impossible. sounds like you accidentally did something to start the car by bumping something and didn’t know what it was. that’s the only way those things would “fix” a no start because a car will start perfectly fine even with just O2 bias or no catalytic activity. Diagnosis ALWAYS WORKS. EVERY TIME. Guess work only works when you are lucky. that’s why you should never guess.

[@am6066]

Great video! Do you have any experience with changing the camshaft sensors on a Hyundai 2007 Santa Fe 2.7L? I have a crank / no start issue w/ zero rpm indication. I cannot remove the Bank 1 camshaft sensor (seems the engineers at Hyundai designed the water lines that go to the cooling assembly to encroach on ).

[@SchrodingersBox]

Plenty of experience with it. The first question- why are you wanting to remove the sensor? What confirmation do you have the sensor is faulty? Did you verify signal output, ground and reference?

[@am6066]

@@SchrodingersBox I have code P0016 camshaft/ crankshaft issue, also P0300/01/03/05; I have fuel, air, spark, zero cranking rpm; only have multimeter and simple OBD reader. Thanks!

[@SchrodingersBox]

That’s all you need! Use the multimeter to check signal. If you have it then changing that sensor obviously won’t do anything.

[@am6066]

@@SchrodingersBox Thanks! We are having some bad weather here. As soon as I can, I will check for signal.

[@nicholaslynch7651]

Dr.Schrodinger can u please do or tslk abt how to change a cylinder head on a dual over head cam like a boss. I seen the chilton but I'm wondering if there are any cheats like there is on single cam

[@SchrodingersBox]

I have a couple of cylinder head videos on my channel. Changing on DOHC, SOHC or pushrod are all similar. It's just a matter of how many cams you need to time.

[@DENicholsAutoBravado]

The comment I made on your recent video about how following the scientific method doesn't mean you're "wrong" to check the part that isn't bad first seemed to belong a lot better here, lol. Wow. I really need my boss to watch this, but he may just remind me again the other day that I should have checked a fuse first. Sigh. ;)

[@SchrodingersBox]

Just tell him that you have a perfect 100% record of always finding the problem in the last place you looked lol

[@ampload]

Would it be ok if I ran a new 14 ga. wire with a manual switch between the fuel pump and Battery... I can turn it on when I need to drive and flip the switch off when I am done driving ? will this work or ?

[@JenniferFuchek]

Depends on why you're wanting to do that... Does it keep blowing fuses? If so trace and fix the fault causing that. Is it an intermittent issue? Generally speaking it's not recommended to bypass factory wiring with other stuff unless certain circumstances.

[@francoisdumaine474]

In order to verify spark, should we connect the test light to the negative post of the battery? Thank you.

[@SchrodingersBox]

Yes you can do that. any ground will work. Some will say it’s safer to use a chassis ground but it doesn’t matter.

[@ampload]

I have a 1994 Toyota T-100 Pickup Truck ( Cranks great but wont start ) I installed a new OEM Fuel Pump & Fuel Filter , Battery with new wires, I pulled out the Circuit Opening Relay and energized it with 12 DC it was clicking good..points where pulling in good... I dont think im getting 12 DC to that relay?when I turn the key and when I checked for 12 DC at the fuel pump I didnt have any Voltage at all ? what should I do next ? Thanks in advance.

[@SchrodingersBox]

Why are you chasing fuel? I don’t see the evidence this is the problem yet. What is your rail pressure? Or simply put 12V to the pump directly and if car starts you need to look for if load or control side feeds or grounds are missing and repair accordingly. Simple as that!

[@scottburgess6417]

It's always the last thing you check, because then you stop checking! Why would you keep looking once you find the problem? So of course someone will say "you should have checked that first". Thanks really like the videos!

[@SchrodingersBox]

Exactly lol!!!!

[@kennethkristensen5537]

Hi Matt. Where can I get the test light led with the orange handle?

[@SchrodingersBox]

No idea hahaha- it was a gift from a viewer. Not even sure what brand it is!

[@webslinger2011]

You could drive it around and have a go at it. Had a small nissan micra that could only go about 25km/hr. Above that, it stutters and wasn't able to go faster. Ihad put in a spare pump I found in the boot.

[@shamrock241r8]

I have a question on the crankshaft sensor, when they go bad or are going bad, will the only symptom be a crank no start, or is it possible for it to start the engine but cause other issues? I have a list of everything i have changed on GM 350 that is powering my boat and still cannot fine cause for hesitation and i believe the slight sound of some backfiring but the exhaust is under water so it is a muffled pop. What i have changed so far: I have a 2002 Shamrock powered by a 2002 GM 350 Mag Horizon Mercruiser. It has a bad hesitation when i throttle above 2000 rpm thru 3000rpm, it idles smooth,starts easy and will cruise at trolling speed ok. I have replaced Ignition coil,cap and rotor,plugs and plug wires, had fuel injectors tested and cleaned,test fuel pressure at the rail and it is steady at 43psi, fuel pressure regulator i believe is ok, when i pull the vacuum hose off while engine is running the fuel pressure increases and there is no gas leaking out of it. I have also had a compression check, that was good and the mechanic found no codes in the ECM. Also replace the pcv valve,egr valve and throttle position sensor. I have not replaced the crank shaft position sensor, do you think this could cause a hesitation under load? Any suggestions would be appreciated.

[@SchrodingersBox]

WHich design is the sensor? Inductive or hall effect? Either way I cover these on my other channel.

[@shamrock241r8]

Thanks for the reply, after researching the difference between Inductive and Hall effect, i think mine is a hall due to the additional 5volt input needed. Thanks for the help and the informative video's, i will go to the other channel and and watch the episode on crankshaft position sensors.

[@CinematicTouchProductions]

HI Shro Recently AAA told me I need new starter, which I believe anyway. For the past year occasionally I get a no crank, just a few clicks or maybe none. I take off both terminals for 10 minutes the it starts. I just learned that paper clip to 30 and 87 will bypass and start your car and I did that and my car did start twice with paper clip, had to try that because it's freezing in NJ now and car didn't start so I wanted to try the paper clip trick I learned in you tube. Then I hear on yet another YT VIDEO that if your car starts via paper clip trick you starter is good??? I think I'm just bypassing selonoid which sticks right???

[@SchrodingersBox]

You need to test voltage drop across the starter. the paper clip cannot tell you anything more than the ignition can EXCEPT if you have an ignition cylinmder problem is all.

[@CinematicTouchProductions]

@@SchrodingersBox Do you have a video that's shows me how to do that you can direct me to?

[@CinematicTouchProductions]

@@SchrodingersBox thank you found your video on voltage drop

[@richard1835]

I was just curious if I could use Propane into a vacuum source to see if a vehicle will attempt to start. Thank you

[@SchrodingersBox]

yep i do it all the time.

[@garysurovec]

I agree, hindsight is always 20/20 in the end. Sometimes fuses just "go" for no reason other than it's their time. I only worry about changing a fuse when it's black on the inside, that means it definitely went open because of a catastrophic failure (short) of some sort. If it is just open and clean looking on the inside I don't sweat it, changing it is all you can do at that point and wait and see if a failure of some sort presents itself more clearly in the future.

[@SchrodingersBox]

Fuses do not "go for no reason" especially over time. You also cannot possibly determine anything by how the fuse blew. You definitely need to change your thinking about this- it is completely wrong.

[@SchrodingersBox]

Completely wrong. This is BASIC ELECTRICAL. There is ALWAYS an etiology for a fuse blowing. ALWAYS. They do not just blow for no reason and you cannot determine anything from the look of how it blew. If as a professional electrician you have just been replacing blown fuses because you think they "just blow sometimes" then you are a disgrace to your field and a danger to people. You are an idiot if you haven't learned this over 35 years pal. BASIC electrical fundamental concept.

[@garysurovec]

Would you consider an engine compartment a harsh environment? An environment where fuses would sustain harsh vibrations and temperature fluctuations that could cause breakdowns in the fuse itself? If not you need to re-evaluate your own arrogant assumptions. Let me ask you this... do parts ever fail in your world? Everything is manufactured so cheaply these days how can we even assume the fuse wasn't defective being overrated in it's current handling capabilities due to a manufacturing flaw? You're the one making assumptions that fuse was in a pristine environment for all these years and perfectly manufactured to tolerances never seen by humans before. IT IS POSSIBLE there is an intermittent short, in the meantime all you can go on is face value, YOU stuck in a new fuse without measuring current draw, using a bulb or circuit breaker, you HAVE a current meter USE IT!!!

[@garysurovec]

You present nothing but straw man arguments and insults, have a nice day.

[@SchrodingersBox]

Omg you are an even worse logistiician than electrician. You clearly don't even know what a straw man fallacy is. Give me ONE example where I used a straw man argument. Just one.

[@wazowski6709]

Hahaha asshats ..... my favourite saying. I love how methodical you are 👍

[@vincentnjowe6214]

You are the best

[@MDI.PHOTOGRAPHY828]

There's idiots everywhere. Those not having to diagnose, often are the fastest to chime in. Good work buddy, skilled trades are slipping away but, you've got it locked in.

[@SchrodingersBox]

Thanks man!!

[@MDI.PHOTOGRAPHY828]

@@SchrodingersBox more than welcome. Obviously the crank no start, brought me in search. Got fuel at the rail, new coil packs (3x repeat on p0300), I do know LIM needs replacement but, its been drivable thus far until yesterday. When it overheated hitting 245*, then the p0300 kicked. Now it cant be started.

[@todayintheshopbanksy5904]

That relay, were 2 terminals bigger? Couldn't tell watching, but it looked like it. They would be load side if so, Would still test before jumping them though.

[@SchrodingersBox]

Yes it was hard to tell but indeed once I found the load side the terms were slightly larger. I too often use this as a quick reference but usually it's more obvious than it was on this car's relays

[@JakeNaughtFromStateFarm]

I say check the fuses/relays first simply because it’s easiest. Got a coworker that had a bus with wipers stopping intermittently. Stole a motor off another one, changed the switch, check the air in the tires (j/k there), etc. After being down almost a week, turned out it was a bad relay. I hear what you’re saying and you’re right: that fuse blew for a reason and there’s nothing wrong with investigating further. I’m just saying always check the easy stuff first. Just my two cents.