2005 Trailblazer 4.2 #6 cylinder misfire diagnosis (spark and fuel test)
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- Опубліковано 20 тра 2012
- This owner of this truck installed a new plug and coil on the #6 cylinder and still continued to have a misfire. Knowing this information affected my approach. I start this process with an injector balance test and confirmed cylinder compression before moving to the ignition system.
Engine Performance Diagnostics chapter 22
Symptoms
- misfire (P0306)
Fix
- repaired corroded power feed wire to the ignition coil
Tests shown
- fuel injector balance (flow) test
- how to test a 3 wire coil over plug ignition coil
- coil primary current ramp test with a scope
- how to locate an open wire
Tools used
- fuel pressure gauge
- scan tool
- inductive low amp probe
- digital multimeter
Playlist
- (Chapter 22) No Spark Troubleshooting, Ignition Coil & Module Testing • (Chapter 22) No Spark ...
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For more information on this topic, I have written a “field manual” called Engine Performance Diagnostics which is available at www.scannerdanner.com as an eBook or paper book.
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Disclaimer:
Due to factors beyond the control of ScannerDanner LLC, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. ScannerDanner LLC assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. ScannerDanner LLC recommends safe practices when working with power tools, automotive lifts, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this video. Due to factors beyond the control of ScannerDanner LLC, no information contained in this video shall create any express or implied warranty or guarantee of any particular result. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user and not ScannerDanner LLC. - Авто та транспорт
Great techniques Paul. Truly a master at work.
Excellent work, and great info. Definitely worth watching
Gracias señor Paul por compartir tan valioso conocimiento.
Very impressive diagnostic skills. I Enjoy watching and learning from your videos. Thanks keep up the good work. Edyn, New Zealand
For sure man, thanks! I haven't done much with scoping fuel rail pressure to monitor injector flow issues, but i am certainly aware of the theory and application of it. I need to do a video on one don't I.
ScannerDanner take care and have a great day Good Afternoon ScannerDanner 😊 God bless you
Great tutorial thanks 👍
From Nick Ayivor from London England UK 🇬🇧
Paul I genuinely appreciated your effort here. I finally have a sense of the coil pack ignition system. I also lust for your Snap-On meter. Thanks big time !
I guess it is pretty off topic but do anyone know a good place to watch newly released movies online ?
@Derrick Curtis Flixportal
@Bennett Jasper Thanks, I went there and it seems like they got a lot of movies there =) I appreciate it!
@Derrick Curtis You are welcome xD
thank you for the comment!
Another great video thanks for sharing Danner !
Great techniques..Paul..
You should, it works. I tried it on a '01 Focus and it led me to the cause of the misfire.
Thanks for the comment and I didn't take it as a criticism at all. Fortunately for this owner it was him who did the original repair, but we do see this kind of thing from garages too don't we? Hey, more money in our pocket is what I say.
Great video.
The camera work was actually very good for you just shooting it out in the field with no tripod.
Thank you for another perfect video!!!
excellent work thanks. I do alot of cranes and manlift computer troubleshooting very similar issues with harness.
Ps always seal the wire pierced with probe. Liquid rubber tape is good. Salt will eat copper quickly with electrolysis.I often find problems caused from previous mechanics poking holes in wires .
Good point and liquid tape is so much quicker,easier & reliable than electrical tape,especially in areas where a wire is close to impossible to access due to being behind or buried by another part.
Mr. Danner. Huge fan for years. You, sur, are the Sherlock Holmes of diagnostic problems. I am surprised that the computer injection test worked given the broken primary feed wire problem. Obviously, the control and ground were intact, and the computer sent the signal, but the pressure did indeed drop which shows that the injector WAS pulsing. Always a fan. Larry
The broken wire was on the ignition coil, not the injector.
The Genisys is an ok scan tool, but the snap-on troubleshooter info. blows the otc "pathfinder" out of the water. As for the Verus, our school is part of snap-ons S-Tech training program so it isn't mine it's the schools and it came with all of the accessories. Oh and we have 10 of them :-)
Thanks again for the purchase of my eBook!
There are others out there, but I don't think you can get a good bi-directional scan tool for less than $1500. Snap-On has cheaper versions of the one I was using in this video. The Solus Pro goes for around $3000 (I know that is still not cheep).
I don't see why not. I've never tried it. Thanks!
i have a multitester a cheap one but digital.i ll check your ebook bro and by the way .i consider my self a technician but you exceed the regular technician knowledge,you know alot of tricks and scanners shortcuts ,,i just want to thnk you for you time,..cheers
EXCELLENT tutorial !!!!!!
if you could do some videos on evap testing on various systems , that would be great due to the different ways that systems operate with pressure or vacuum and how it changes the way you diagnose them
IT'S OK, A MONTH AGO I WAS WORKING ON A 2004 TRAILBLAZER AND COULDN'T FIND IT, NOT EVEN AFTER TAKING THE INTAKE MANIFOLD OFF, WELL IT WAS THE #4 INJECTOR THAT WAS CLOGGED, I DID AN INJECTOR BALANCE TEST BY GROUNDING THE INJECTORS WHILE THE ENGINE WAS RUNING AND NUMBER 4 INJECTOR DID NOT CHANGE WHILE ALL THE REST STALLED THE ENGINE WHILE FULL GROUND, NOT THE BEST CHOICE I MADE BUT MY BOSS WAS STRESSING ME FOR AN ANSWER, LMAO!!! THANK YOU BRO!!!!
Paul, the 2004 TrailBlazer does not have a M.A.F. Sensor. It is a speed density system. I LOVE your methods, & videos! I have an Industrial Elect/Instrumention background, so I work on my cars & motorcycles.
Paul, your my hero!
Great video master
Cool man, thanks for the tip! And the comment.
Paul, you are a Jedi and I am your padawan learner. I work on cars, and I know how hard it is to film and work at the same time. Keep up the good work; you have a small following it looks like.
funny you ask. I am working on a video right now for this very thing. I cover trigger, trigger slope, trigger delay, triggering on a separate channel. I'm still working on it though and it may be a few days or a week before I have it done and uploaded. Look for it and thanks!
Thanks so much for posting this video, other wise my husband and I would still be out there screwing around... This was EXTREMELY helpful!
Hi Paul
Excellent video.It would make your life easier to use a short and open finder like ECT 2000 so that you don't have to make so many holes in the wire.Just Purchased one.It works every time.
I love you
Thank you my friend, I hope the following gets larger :-)
Sometimes and on some manufacturers the injector is not shut down. And on initial start-up and at WOT the injectors will be allowed to fire again.
Thank you very much for this video, i have the same problem on cylinder #3 i done coil change,injector change position, new plugs and injector cleaning. I really don't know what the problem can be... but I am going to check the harness.
thanks agin great video...
Good question, no there was not, only a #6 cylinder misfire code. There is no ignition confirmation signal on this design, so no primary DTCs.
Thanks for the compliment on the video!
Freaking amazing man! Just freaking amazing..
nice work
Yes you do my friend. And I just updated it a few weeks ago, you got that message right?
Awesome video!!!
awesome video, ive watched all of your videos twice and some maybe even more like 10 lol... I found ur vids. approx. 6 months ago when i got my own verus, needed help with navigation, i was use to the shops modis. so thank you! Def. want to purchase your e book.. 1 more thing, ive actually seen this same problem on an envoy was a no start, found low voltage at the coils, ended up being similar 1 ft away from fuse box the pink wire was just up out of the loom and it rubbed causing green weenie
video, yes.
and show the relative compression test with the sensor in the tailpipe.
Woow awesome scaner
Good question, no it does not. Some secondary "leakage" problems cannot be seen in a primary ramp.
Thanks bro
Hi Paul, Great video, Very informative, just a thought though wouldnt the pcm just shut down the number six injector if it saw a misfire in number six coil.
cool thx for the tip
Your videos is Good
My 2001 Chevy Trailblazer also having a cylinder 6 misfire. I changed all the spark plugs and still the same
I got a 2007 trailblazer with a inline 6 cyl. Engine and also misfiring on both 5 and 6 cyl. I checked spark plugs, I had switched out the coils and also had taken off the intake manifold to test the ohms on the injectors. No vacuum leaks either I even send out the computer to get it checked out and supposedly it was bad so I bought a reman ecm. Had it reflashed. While reflashing the ecm the tech. Who flashed it was having a hard time because it was kicking out the scanner that he had. Until finally got it to reflash. And still the same issue... I'm gonna check the wiring now hopefully I'll find the solution
Did you find a corroded wire?
Hey I notice you use varius types of snap on tool could u do a review of the scan tools u use and why u all ways switch it up with the tools. Thanks
I know, I don't have one, I have to get one for sure!
Ok, so no separate cruise control unit. Are there any trouble codes for the TPS or vehicle speed sensor?
Well done. The last shop should have found the break or start to watch your vids to find out how to do a repair the right way.
very sweet
Paul, on some Ford models that have the sensor in the fuel rail (which I believe is a pressure transducer), you think its possible to do an injector balance test while monitoring the pressure on live scan data? It would save the time of connecting a pressure gauge, wouldn't you think. Of course you would have to make sure that the sensor is working. God Bless your channel we sure need more technicians like yourself.
Nice one.
keep me posted on what you find
Paul, I'm still learning scopes, question, the trigger is primarily used to get the waveform detailed as one picture of that event? If so, what tuning is involved to do this with a scope?
Great info Dan. My snap on guy came by today and I see you have the Verus. I am demo-ing the OTC Genisys but find a bit clunky for the money. What would you suggest? Did your Verus come with the Amp prob, piercing wire tester, etc? Still printing out your text book btw, lol.
Is this an electronic throttle body or does it have a throttle cable?
Paul, you probably already know this- Pico(and maybe others) have a fuel rail pressure transducer for injector testing.
would be handy for vehicles without the injector test function.
I wish I could help you further, sorry. Possibly an reprogram issue? Possible glitch in the TPS even though you don't have any codes? Maybe it also could be a tire size issue?
Thank you :-)
Figure it out yet? I haven't replaced my coil pack yet, but I'm concerned that won't fix it. I've done everything else you mentioned. Mine doesn't start misfiring until it warms up.
barometric pressure in inches of mercury. what is around 29 or so at sea level
This is where the Power Probe ECT 2000 is a god send
Your a genius...
Hi Paul, I'm a service tech looking for a good wire probing tool and I like the way yours is made can you tell me what brand it is or if you even have a part # for it, I would appreciate. Thanks.
I can't comment on cost but the equipment I use is:
Picoscope Automotive 4000 series
Snap-On Verus
Snap-On Vantage Pro
Snap-On Solus Pro
Mitchell-On Demand (information data base)
Some other resources and websites I use
iATN, autonerdz, picoauto forum
ScannerDanner
How do you diagnose the misfire without the high end scanner
When you read the map value and subtracted from 29, where did the 29 come from?
paul. can you show us how to properly solder or fix wire connections. thanks >.
You dont need 5K snapon scanner to perfrom injector balance test, there is one at OTC to do injector balance test which cost 80 to 100 dollar in ebay. Paul have video about how to use injector balance test using such tools. To test ignition you can perform ignition control signal test using Hertz mode in multimeter, and simulate the control signal just with test light. If you need scope search for OTC 3840F 2-Channel sope u get it for 450 dollar. Good luck.
Hello, Paul. I have read that you can tell an ignition misfire and a lean misfire by looking at the rear o2 sensors. With an ignition misfire, you will have a bigger drop. Can't you also use the injector pulse data to make the difference? I mean that if the scan tool shows injector pulse width within specs : 2ms to x ms.
about to go try this just by inspecting wires, been having a cyl 6 misfire for almost half a year
I have a 05 Trailblazer with a cylinder 6 misfire. It has been running like this for about 8-10 months. Did you ever figure out which repair needs to be done to correct this issue?
Me gustan tus vídeos son d gran ayuda
+Cesar Alvarado sorry brother, I don't speak your language
asui
,
son de gran ayuda?? es lo mejor q encontraras men, scannerdanner is the best ...he is the boss
Cesar Alvarado he says he owes America $700,000 in taxes
The coil didn't fire the spark plug, so you had no combustion in that cylinder. But the injector was injecting fuel all this time. This unburned raw fuel was being dumped in the cat, damaging the cat.
Who gives thumbs down for a video like this?
Only haters n parts changer lmao
Milton Solis Haha! Well, I can't do that... thumbs down!
Кодове грешки за Chevrolet trailblazer
trolls
hey DAN! if i buy the same scanner you use,the snap on!.. i live in peru and if i import the scaner here for my use, do you think i can use the scaner with the cars on my country market,,sorry for my english. i know your scaner is multi brand but i dont know maybe wont work here even if the scaner storage asian brands too.
would a head unit gopro work for filming?
Fucking awesome information brother. Thank you!
I have a 2003 gmc envoy 4.2 just changed all the plugs when it started missing but when im driving at around 55 it still misses or around 1500 to 2000 rpm. idels and starts good
+Pandora Graham one of your coils is most likely going bad. move the coils around and see if the misfire follows it
Im curious, how does that tester ground? does it not need one?
A tone generator would have made finding the open alot easier and no holes in the wire. Great Video
are these things all home mechanics have
Paul, I can understand not being able to check coil control if you don't have a scope to see the pattern. Checking power and ground should be basic, how much does a $7 dollar test light cost?? On the other hand seeing how the wire was, there is a possibility that maybe there was voltage at the coil when the first test was done.
ok, will do then, just give me some time
lol nice! Thanks
From the misfire, what possibly made the cat go bad?
Great video.If an individual doesn't have a nice scanner but just a small handheld one that does show live data,but not individual cylinder action like yours and if code p206 & p306 are present with rough/choppy idle that popped up out of the blue,is it likely an injector and/or injector harness issue & likely not at all related to a coil issue?? The scanner & multimeter are my only two tools to work with so what steps would you advise for me to take and can live data help me at all if my scanner doesn't show each cylinder individually?? Thanks for any help you can offer.
Correct! Attack the injector code! Injector, wiring, computer driver
@@ScannerDanner
Well great news man.As soon as I pulled the air resonator off,I immediately saw a wiring issue that looked as if it had been chewed on and as an added evidence bonus,remnants of an acorn and shavings from the wires insulation were resting on top of the valve cover.Obviously a chipmunk or squirrel has been keeping its teeth filed down by using my damn injector wire. When I noticed the wire was yellow/black in color and referenced a diagram,I was instantly happy knowing that this was almost 100% my culprit seeing how it started out of the blue just one or two nights after I had noticed my dog eyeing a critter scrambling across the top of my garage roof.Needless to say I'm jumping for joy right now since I was really dreading that damn intake removal & the Trailblazer is running like a top again.Thanks for the advice and now I'm updated.
@@wbrockstar9550 heck yeah man, nice job on your part
@SCANNERDANNER, WHERE IS THE SHRADER VALVE ON THIS ENGINE?
I want your scan tool.
It was the owner who tried to repair it on his own.
Nice work Paul!!! This is not a criticism but I think I would have started with a wiring diagram and started at the source and worked back.
Please tell me that the last garage didnt charge for that load of crap (I bet they did!!!). I see this time and time again where its been to another garage and they go far to deep to quick without checking power/signal/ground first. I spend to much time apologizing for our profession where some fool cant check basic thing first, MAKES ME SO MAD!!
Are those butt connectors on that coil wiring?
Sorry Paul, I commented before I watched the entire video! DOHO! 11.18.13
No problem Steven, Thanks!
very great vid ,,,how much do those scopes sells for ? dont sugar coat it LOL
What type of scanner do you have
Man I can't remember? It was right out in the open though. I guess I should have showed that part, sorry
Post a link to the tools used please
www.amazon.com/shop/scannerdanner
www.scannerdanner.com/tools.html
I worked in a honda legend i think 2003 i dont know.in the front chassis support was a label that said "EXTREME CAUTION when measuring with multitester or voltage probes ,can burn ecu and parts" so when i read that ,i just leave IS THAT DIFFICULT TO MEASURE A CIRCUIT IN THAT KIND OF CAR? ÒR I JUST NEED THE MANUAL TO READ THE PRECAUTIONS BEFORE I GET MY HANDSinto?that labels and manuals that say"high resistance multitester ,use just low impedance voltmeter drving me crazy
Were those PCMs not programmed to shut down Injectors with misfiring cylinders?
some do, not sure about this one