Misfire from a sticking fuel injector (no fuel misfire)

[@mike-yp1uk]

Hi paul, just want to give you a big thanks. Since joining your channel things have changed in my career. I used to be a frustrated parts changer. Diagnostics were to much for me. After buying your book and doing all your free videos i joined your premium channel for two years drilling this stuff into my head as i do to this day. I want to thank you now i am opening my own father and son garage. A&M auto service and sales. You opened my eyes to the world of diagnostics. Everyday i must study or i lose my edge but you explain in great detail and thats what made it stick. Thanks again for all your efforts. You are a great instructor.

[@ScannerDanner]

This is so awesome to hear. Makes everything I do have real value to me. Thank you so much Mike!

[@felixarmendariz7964]

Scanner danner is an Einstein at his work.... the smallest detail to be great. Makes work more effective.more productive. It equals to more profit.

[@keithsrepairinc1608]

This injector test worked perfectly. Found P0307 code on a 2001 Silverado 5.3L set because of #7 injector stuck--no pintle hump. Your test videos help us all to learn more. Making better mechanics every day!

[@jaimecarbone6580]

This a dynamite video, the instructor gets an A, his analysis of the problem it's so easily explained by him, Thank youI just learned a lot in a just 12 miunutes video.

[@lanceair151]

I can certainly vouch for the Chevron Techron in terms of unclogging fuel injectors. I recently repaired a 98 Toyota Avalon that had sat for ten years. The fuel tank and pump assembly was completely rusted, but old fuel was still in the lines up through the injector rails keeping moisture out and the rest of the system from corroding. After replacing the tank, fuel pump, filter, blowing the lines, and adding fresh gas, the engine would not start. Adding a bit of fuel in the intake proved the engine would fire right up, so I definitely had gummed up injectors. I added a bottle of Techron to about 4 gallons of good fuel and cycled the key a few times to push the mix into the fuel rail, then cracked the line open to drain the rail and repeated that draining/filling process two more times to push fresh mix into the rail and injectors. I let it sit for 30 minutes and started the vehicle. It went from no start to running on 3 or 4 cylinders. I snapped the throttle a few times, shut it down to sit overnight and when I fired it up the next morning the car ran like a sewing machine. Never had another minute trouble from it.

[@PicassoPete]

Brilliant video. Nice to see the injector waveform normalise after the mechanical tap with the screwdriver.

[@muskman55]

Such an incredibly thorough video relevant to any fuel injection system

[@MaicSalazarDiagnostics]

This video guide me in order to fix a Ford E-250 with the same symptom! You are awesome! Thanks again for all your help! Injector 5 misfire! Did all the procedure as you show here! I even got it unstuck! Replace the bad injector, now Van is running like a charm!

[@mamoudbah6558]

Man you are too good You know what, you are the best teacher i have ever seen

[@ScannerDanner]

Oh man, thank you so much. Glad your here

[@mamoudbah6558]

Thanks a lot man

[@mamoudbah6558]

I will like to get in touch with you

[@danielcotayo4357]

I like the scientific approach to solve car's problems using such advanced equipment as you do on your videos. It is a more accurate way to find what is the cause of a malfunction in the system. I really like your videos.

[@ScannerDanner]

Yes, that is also an acceptable method, however noises transfer and you can hear injector clicking from the injector next to the one in test, especially with the sensitivity a stethoscope provides. This is why I will use a long screwdriver for the sound test as it is more muffled.

[@ASEDoc]

Excellent video. I'm an ASE Master Tech L1 diagnostic specialist and watching these videos is like a refresher course. The fact that you're using the Snap On scanner/scope is cool since I have the new Modis Ultra which is similar to your Verus(though I see the Verus may a little faster and more user friendly). Good work man!

[@Crzyfrlss1]

Thanks for posting this. I need to do this test later today and needed a refresher tip, was trained many years ago for lab scope diag. but was never able to put what I learned to use until a recent purchase of a Triton D8

[@jonteague7495]

great video, we need more Tech's that will take the time to learn these things about scan tool operation. great job sir!!

[@mrbibstoo]

Excellent presentation! Very concise and right on track. Thank you for presenting this in such detail. Might I also add that in many cases I have also been able to find a stuck pintle by using a stethoscope and listening for the audible "click" when the pintle closes. Much faster to find than hooking up a scope, just not quite as accurate.

[@RandallFlaggNY]

One of the best videos I've ever seen on YT.

[@ScannerDanner]

SIA 2000 and it is made by snap-on for the Vantage Pro and Verus. There are other adapters that are less expensive that you can view single cylinder events, but this thing is awesome for parade type waveforms of all the cylinders.

[@SuperGusi1]

your the best teacher by far keep up the good work.

[@ScannerDanner]

Thanks man!

[@ausmartin1]

Excellent informative video on the Ecotech, here in Australia most are fitted with Bosch Injectors and way less problems, but like anything with age etc. anything will fail.

[@svenvos3971]

Real nice explanation of this diagnostic procedure.

[@ScannerDanner]

@JohnxWaynexGacy If you mean what they should look like, the answer is yes. Did you watch my injector driver designs video? It is a classroom lecture on injector waveforms directly out of my book. This video is just some of the injector material that is there. I have a complete section on injector testing too.

[@tiztiz5839]

12 years later from your video Paul, i just had this happened this to me exactly chevy 3.1 all i had was. p0300 but what it was cilinder 3 injector stuck closed after days of unexperieced diagnosis i remembered your video , i smacked the injector fixed in two seconds , i am gonna try injector cleaners will see if it stays running

[@ScannerDanner]

BG 44K Fuel system cleaner was the fix for this one from what I remember? Thanks!

[@tiztiz5839]

@@ScannerDanner will try , stay strong paul.

[@Enrique_Osorio]

Thank you for this video and teaching me more about fuel injector waveforms. I gladly edited my most popular video on fuel injector waveforms due to what I learned today.

[@ScannerDanner]

@MrToolean sure. it uses a high resolution crank sensor. one that has enough signals on it to allow the pcm to monitor acceleration rates of the crankshaft between cylinder firing events. a frequency increase =the cylinder fired. a frequency decrease = misfire

[@Belinda-ix8wx]

I always wish Mr Paul I will meet u in person one-day,I study production engineering but I later switched to Auto mechanics through watching KZbin videos..I watched Ericthecar videos and he mentioned Schrodinger box and through his videos he also referenced the almighty Scanner Danner.Schrodinger box automotive give me a Free subscription to his channel which I appreciate it a lot.i am proud auto technician now...thanks 🙏🏾👍🏾🙏🏾👍🏾👍🏾🙏🏾👍🏾👍🏾 I bought ur soft copy of your books and it has drastically improved my diagnosis ability....

[@ScannerDanner]

Stuck open would result in the same pattern (no pintle hump). However the symptoms would be drastically different. Check out my video on "Stuck open fuel injector". This one wasn't stuck open mechanically but was electrically shorted to ground so the waveform would be completely different, but check out how it ran!

[@richardballinger517]

Brilliant video, good explanation of what your seeing on the scope, could have done with this video last week. My motorcycle didn't seem to be firing on #3 cylinder. I used my portable scope (electronics engineer) to test this that and the other on a fuel injected bike for the first time.

[@ScannerDanner]

Will do, stay tuned and thanks

[@harold6863]

You explain everything so clearly. Thanks so much.

[@ScannerDanner]

@CoolasIce2 I have never seen a stuck open injector other than when the control wire is shorted to ground, causing a constant magnetic field. I think the fuel pressure behind the injector pintle would force it to close, maybe that's why.

[@marceloromero9012]

Thanks for the video, clear explanation and procedure!

[@ScannerDanner]

great compliment, thank you so much!

[@ViewThis.]

Wow! This was more interesting than a million dollar block buster movie.

[@ScannerDanner]

@500hpsi Yes, you would have. I attempted to show that too but I was getting too much interference with my amp probe at the time.

[@Willyconrad]

Excelent video and explanation. That’s the way to teaching

[@ScannerDannerPremium]

No, as long as the winding and power and ground are good. Pintle hump location on the ramp is also variable and differs with each injector. IT is something that you would compare to other injectors on the same car only.

[@batinhbngo]

thank you for sharing your knowledge. Good explanation. Please share more.

[@ScannerDanner]

as long as you stay under 220 your fine. nothing wrong with the temperatures you have

[@thesetruths1404]

Hi I have a 2007 Liberty 3.7L V6, 117,000 miles. Owned it since 67,000 miles. It operated perfectly for the first 30,000 miles and then it started getting a #1 Cyl misfire code P0301. It also seldomly gets a #1 cyl fuel injector circuit open P0201. It must be a very mild fault as the misfire freeze frame data shows it always happens at less than 350 rpm and when cleared it comes back immediately at next startup, cold or hot. So it seems to only happen once on startup as its moving up to regular idle speed. The miss isnt noticeable when driving or idling. Its getting 15.5 mpg fuel mileage. Doesnt burn oil. Doesnt smoke. Has great power. I've changed plugs and coils but no difference. Cleaned air intake, air filter, and ran cleaner through system. I've cleaned and inspected the injector plug and all wires but no difference. Dry / wet compression test of #1, 3 and 5 cylinders all read good: 160 / 175 psi. I'm wondering if there's a mild wire defect for that injector, or just a flakey connection somewhere. Has anyone tried to use a new set of compatible gauge wires and run them to a place closer to the injector control? I can't see where the wires go though. I'm not sure if I should just live with this, or troubleshoot it more. I don’t care about the engine light as we don't have emission requirements. Now that I know the compression is good, I'm not so worried about it. Any suggestions of what to do next? Thanks!

[@michaelr6205]

Great stuff as always from Paul!

[@alkhashtee]

It is really nice tools and great job. Thank you so much for these details

[@trublue2319]

Nice and fast good for us techs who use the snap on knowledge is power

[@chriscarshunting]

Very nice. Great knowledge. Thanks for taking the time to share...

[@Joe_1971]

Great video Paul...i learned something valuable.!!!

[@ScannerDanner]

For sure, but this wasn't hard. Just a different approach. I feel the more methods of testing you know how to do for one particular problem the better prepared you will be. In my fuel injector testing section of my book. I list and describe 7 different types of fuel injector tests.

[@ScannerDanner]

You re-uploaded my videos, which is basically stealing money out of my pocket! I gave you permission to link my video NOT recopy them and make them your own with completely different web links. I have taken action against you for this.

[@ScannerDanner]

most likely this is from an ignition misfire and the PCM is protecting the cat. by shutting the injector down. the way you can tell this is what is happening is by rechecking inj. pulse on initial start-up. If it comes back for a few seconds, then it is NOT an injector problem.

[@ScannerDanner]

any scope you can do this with

[@allpromechanic1218]

the best videos on YT

[@Jursaw]

Freaking intelligent guy! Learned a lot from your videos!

[@ScannerDanner]

im ok with that. thanks for asking Merry Christmas

[@ziadabdelmuti9547]

Great video thanks for the useful information

[@ScannerDanner]

What was done as part of the "tune up"?

[@CoolasIce2]

Good info. What would you say the percentage is of stuck OPEN injectors vs stuck CLOSED? Maybe 80 % open vs 20 % closed?

[@juanstrongman]

another great vid! you should put these on a DVD I would buy it!

[@dreamer2355]

Another question. Without using a lab scope, could you also attempt a fuel injector leak down test using a fuel pressure gauge and a manual device to activate the injector such as supplying 12v to the injector after disconnecting the injector wiring connector ?

[@tomywoo4671]

It's cool to see how a stuck injector would show up on a scope

[@scientist100]

Thank you for the redirect. It helps to see these waveforms. What would it look if the injector was clogged or if the fuel pump pressure is not enough to open the injector? I need to go back to basics from your book for sure and get to see the waveforms as I get more hands on on bad signals that I'm not 100% certain if they have a certain characteristic.

[@ScannerDanner]

A lean misfire on a secondary waveform will look like this stuck closed fuel injector. Whether that lean condition is from a vacuum leak on one cylinder, a restricted injector, or low fuel pressure. Obviously a low fuel psi condition would result in ALL of the cylinders looking like this. Check out chapter 1 for some examples of secondary ignition misfires. I have some lean condition examples in there as well. Thank you!

[@MrToolean]

Just recently found this channel, and I LOVE it! Dumb question, when you say that misfire's are calculated off of crankshaft speed, how does that work? Can you explain a little more about how the ECU calculates that? Thanks!

[@edgarcastaneda9086]

Sr. Danner could we expect the same hump if the injector was stuck open? thanks for sharing your knowledge with all the youtube community, greetings from the border

[@lifeInProgress_8020]

@ScannerDanner can you by chance do a video on capturing a bad injector on low amp. probe. A good one would dirty injector that is causing a lean condition. also what is your option on amp probing starter for testing purposes? would it be accurate for diagnosing a failing starter? thanks

[@irvingcarbajal1433]

What does this injector problem do to fuel trims? Btw, thanks for your videos, they are awesome 👌

[@lifeInProgress_8020]

good info. would you by chance captured that same injector using the low amp probe? I to see how the pintle opening hump would look like. I assume that there would be none since there was no pintle hump on closing.

[@theamazingjoshchannel4420]

rcabaccang Ivanova

[@robertmccully2792]

Great video. If you have feed back for all injectors capability and the tool to read them. Wish i had a newer vehical and the latest snapon tool.

[@mustafaqays8]

Thanks for this helpful video. How can the ECM detect the misfile ? Is it mentioned in the book ?

[@masksareforwhitepeopleonly4311]

Hey Dan, good video do solenoids lose their magnetic strength over time causing slow pintle response, and can this be seen as pintle hump placement on the ramp i think i heard this in one of your videos thanks DT

[@mikalf1]

can this testing be done with a regular oscilloscope or do you need a special tool like your verus and the settings that come with it

[@DAQUAN88]

What is the name of the Secondary Igniton adapter you are using and where did you get it at?

[@Farseer1995]

Hello, ScannerDanner, would this also work on diesel injector testing? I know they have different voltage(?) so I'd have to adjust the settings for that, but would they operate in a similar manner i.e. be grounded, have the spike, and pintle hump? Thank you!

[@CHewYue]

pretty interesting to see that the scanner stores previous data of previous misfires per cylinder

[@amorozzo70]

wow,you are the man.great video

[@JisINSANE3]

Well, I have a 09 ford flex I started noticing a random misfire until I started on the gas for the past few weeks. Then it clears up. today no. Constant misfire. Replaced the plugs and coil no go. The injector is not clicking. I tried smacking it a few times with my wrench. Nothing. The engine felt like it was misfiring on more then just the cylinder #5 the OBD was showing on the way home but it did not throw any other codes. Well, I just ordered all 6 injectors and doing it this weekend. I'm hoping its just that and not the damn fuel pump. I would not think so since its isolated to this one cylinder and using a sound tube there is no clicks from this injector. I'm thinking the extra vibration was the injector was getting stuck open shortly and it was hydro locking then going back closed. Strong fuel smell then no fuel smell.

[@sterline80]

Scoped a 11 caravan known good today for fun, no "pintle hump" on this one. not sure if it was because it was a dif design or just so new but wasnt there

[@TheRealFrankWizza]

does your book examples of "classic waveforms"?

[@kruno45]

just curious got a ford taurus 3.0 DOHC misfire on number 4 can hear the injector but seems to shut down when warm no sound does this sound like an injector or driver problem.

[@desertfox2020]

How would I go about recognizing a stuck OPEN injector without access to a lab scope?

[@JoseSandoval-ic5xe]

Hi can a problem like this with one injector cause negative long term fuel trims and lower engine power on a 4 cylinder turbo engine? Can a leaking fuel injector cause same symptoms? Awesome video loved how you explained everything very clearly. Thank you

[@ScannerDanner]

A leaking injector can definitely cause negative trim numbers, but typically won't cause low power complaints unless the plug is also fuel fouled

[@alanw5879]

What's that adapter tool youre using, it's like a 4 to 1 adapter, is that from aes wave?

[@bodeine454]

Thanks for the video! We just purchased an '03 Buick Rendezvous w/3800 SFI engine and suspect a stuck injector. It has a definite miss fire in one of the cylinders and I've changed plugs and wires and checked all of the coils to no evail. I don't know where you tapped on the injector at since it's under the intake manifold. Will you explain how I can access it in order to tap on it? I saw you tap on the manifold but not the injector...Please help!

[@ScannerDanner]

The 3800 wasn't known for injector issues. More likely from your symptoms it is a coil issue.

[@bodeine454]

I'm sorry, I had that wrong, it isn't the 3800 it's the 3400 3.4 liter V6....

[@bodeine454]

ScannerDanner I figured out the problem, I should have checked this earlier on but I've never had a vehicle with crossed spark plug wires. Two of the wires were on the wrong coil lead...

[@Theview24]

Paul, do you recommend any exhaust tail pipe analyzers?

[@user-ku5dr3vy4w]

could you do a cylinder balance test,also drop each each cilinder injecter one at a time,watch scan

[@mariocorona6836]

I know u mentioned chevrons techrons inj cleaner, What do u think about Lucas injector cleaner?

[@alexscarselli3240]

Great Work Dan. I'm having a problem with my 2004 chevy sub. 5.3 L 64,000 miles on it whic is an engine miss at COLD Starts. Sets engine light. At 2100 Rpm's at Highway speeds of 65 to 70 Light Flashes, so I slow it down and back to steady on. Once engine warms up engine seems to per. Got a scan tool, Bank 2 has a higher LT than bank 1 being 10 to 12 and bank 1 is at 8 to 9. When rev. engine @ 2,000 + rpm's noticed bank 2 cat. sensor #2 starts dropping from 740mv to .045mv? back on idle it comes up. cats are clear no pressure before it. changed that rear sensor, same effect. # 8 cylinder is the one showing up as the code P0318. #8 misfire. Snap on tool shows 18,000 total . Changed all of # 8 items with other cylinders. # 8 still comes in as misfire. Looking at Injector #8. Tried Inj. Cleaner LUCAS. Same with several treatments. Tried Propane intake test. I didn't notice any change in RPM. These are few of the brief things to mention that I been trying. In open loop I under stand its a set program in the computer. A rich Mix etc. I understand a lack of fuel could be an issue. Fuel PSI AT 55PSI. I'm Thinking it can be injector related because of the HIGHER Bank 2 LT FT and the reaction of sensor 2 after cat? Can sure use your help on your input Thank you Alex [e-mail]

[@ScannerDanner]

I am directing all help requests to my forum. Sign up (it's free) and create a new post. Be sure to add a name under "alias" as this is the name that will appear in the post. Here is the link to the forum. www.scannerdanner.com/ForumRetrieve.aspx?ForumID=3226

[@prospexican]

great video, i knew the snap trick, wave form, question, whats the yr make and model on this vehicle u testing? if u remember, algo is that a 3.8? w EGR?, ups never mind about my question, i saw the EGR, that one creates too much heat to number 5 injector, that's the main reason of #5 injectors going bad.

[@shopyard87]

What tool did u use 4 your ignition testing? if you don't mind me asking. I have a pico scope and the genisys lab scope. I just haven't seen one like yours.

[@ednewell1847]

Its a Snap-on Verus scanner and scope with a SIA2000 ignition probe

[@JD-526]

When you use an amp clamp on a fuel injector as you mentioned in this vedio, do you hook to a specific wire or can I just clamp the entire loom to the individual injector. I watched this video 3 times before I picked up on that. Thanks Mr danner. You are a great teacher. I need to go premium.

[@ScannerDanner]

You won't be disappointed my friend. Thank you!

[@jplkenny]

I have a 00 centry with a 3.1 and i recently tuned it up. Directly sfter the tune up the mileage got worse and there was an intermitent hesetation or sputtering but so far it hasen't set any codes. I was wondering if you had any ideas? thanks

[@slicknick4140]

It only added 198 misfire events to the other side,not 200!! We have been lied to 🧐 Another great video 😁 Amd by pintle hump you are referring to the 'current ramp' correct? (Cant believe this video is already 9 years old.. i remember when i first watched it when it was 3 years old

[@cheese7837]

excellent video

[@sheeptoshepherd4624]

@ScannerDanner What are some norms causes of no fuel miss fires?

[@ScannerDanner]

faulty fuel injector, wiring or computer driver

[@jackross7_11]

I have a misfire in cylinder 2 and a small evap leak on a 6.1L Magnum. Why are you doing all this if u can just take a stethoscope and listen for the ticking of the injector? I am stuck I changed the plugs, the coil, and switch the 2 and 4 injectors.

[@brianwinter1453]

Look at fuel trim also would be high because computer will compensate for lack of fuel. O2 will be a little lean on that bank 1 also no hump on from pintle is a clogged injector..

[@jasaircraft]

awesome vid and tools!

[@billwilliams6338]

SCANNERDANNER, can you show on the oscilloscope how to measure the "dwell time" of the ignition coil and spark plugs using the oscilloscope. Is the Dwell time the interval space between each ignition coil voltage waveforms

[@ScannerDanner]

dwell time is simply the time that primary current flow is occurring

[@billwilliams6338]

@@ScannerDanner, but where is the "dwell time" when looking at the ignition waveform? I don't know where to look on the oscilloscope waveform where the dwell time occurs do you know where it is?

[@billwilliams6338]

@@ScannerDanner Can you please make a video explaining dwell time because i don't understand what is dwell time and how to look for dwell time on the oscilloscope waveforms please

[@ScannerDanner]

Voltage waveform or current waveform? Primary or secondary?

[@billwilliams6338]

@@ScannerDanner can you show in the video how to measure the dwell time of the primary waveforms and secondary waveforms because i don't understand how to measure the dwell time and how the dwell time changes the RPMs

[@cfauvel]

OMG that was awesome....I want to go back to school !!!

[@Evesautomotive]

Nice. Wonder what the fuel trim on that bank was.

[@ScannerDanner]

+Eve's Automotive positive numbers I'm sure

[@vg23air]

the techron is the ONLY product that will free sticky intake valves, I wouldn't doubt it is best for sticky injectors too.

[@danielraymadden]

Dan good video to the point.

[@BoostedMoose517]

Ironic this came up in my recommended video's after I just had a 98 Century come in Friday for a Cylinder 3 misfire. Started off checking for spark with a test light to ground and pulling plug wires off the coils, All had good strong spark but #3 i had no change. Car had all new plug wires, plugs and coils on it so someone was trying to fix it before it came to the shop I work in. Next step I did was go after fuel so I put a fused jumper in for the Injector fuse and had all 6 currant ramps. Didn't have a tool to fire the injectors to check for fuel pressure drop so i unplugged the bulk head connector for all the injectors and manually fired them with my power probe and sure enough #3 did not have a chance in pressure. Tapped on it with a screwdriver just like you did and BOOM misfire gone.

[@ScannerDanner]

nice! Just be careful manually energizing the injectors, you can easily flood the cylinders with too much fuel and cause a hydra-lock condition. Also, on some injectors, you can actually hurt the windings if you energize them for too long. Good find though my friend and great job.

[@BoostedMoose517]

@@ScannerDanner Agree 100%, Just did what I needed to see to get a 100% confirmation injector is was no good. Love the videos! Living close makes me hope one day run into you and get a chance to talk sometime! You, Eric @ SMA, Ivan @ Pine Hollow, And Keith @ New Level really helped me with diagnostic tactics!

[@robertfloresjr8837]

Great job!

[@jasonmcnamara2079]

brilliant, it seems whats the point of diagnosing without a scanner or oscilloscope.

[@Tmanolis]

I couldnt agree with you more than I do. However there are a few simpler "ballpark" tests that would be useful when an oscilloscope is not available. My favorite test is the screwdriver test, you just put a long screwdriver firmly against the injector and put your ear against it, you can hear the injector clicking loud and clear. You can compare the sound of each of them with the rest, and 99% you will get a true result. My car had 3 new injectors and one old, all of them failed randomly (due to age and poor fuel quality I think) and caused subtle misfires. When the symptoms reappeared, used my screwdriver to guess beforehand which cylinder had the old worn injector and I was correct.

[@jasonmcnamara2079]

yep there are some good tricks to be used that can be semi diagnosed in this way to a point you hopefully find the solution. Can use this also on items with bearings as well like alternator etc if your game enough. But the majority does need quite the understanding of the complexities of the workings and relationships of and between so many sensors etc on vehicles these days. Even having a basic understanding can go a long way too, people just need to educate themselves a little more. Some things to work out do seem easier than others