VW Polo 1.4 Mystifying Misfire

James Dillon tackles a diagnostic job which was booked in to the workshop for the ECU to be swapped. This is where the fun begins. The video covers testing tips and techniques including gas analyser, oscilloscope, ASNU and a little bit of diagnostic brainpower.

[@marinkojezabek2555]

there are a lot of workshops out there that have no idea what they're doing apart from playing swaptronics until they eventually find the cause.

[@musicandfender]

Love that Pico, brother. The capture rate picked up a really clean looking choppy declining waveform on that injector, and you did an excellent job of quickly and efficiently explaining. Also, a fantastic job showing viewers the mechanical/flow faults. Gotta say, out of the vast vast vast majority of youtubers, you have a super awesome pacing and explanation to your videos. I dunno if you're a teacher, but you'd make a great one.

[@pwnhorde]

This is happening on my 1.4 FSI polo on cylinder 2. This video has helped me understand exactly what the problem is many thanks.

[@philiprutt3129]

Great video using 4 different tools showing a good repair process. Thanks

[@shersshers8179]

Super Diag video.I found your process of fault finding fantastic and inspiring thanks so very much.

[@motorcyclesandridingfree2899]

Very well done excellent diagnosis

[@michaelhawthorne8696]

Just watched this again...saw more of the video this time...Nice diagnostic and nice kit to prove it.....

[@stevenbarrett7648]

A disturbance in the field, may the Force be with you !. On a more serious note that’s an amazing diagnosis of the problem, well done !

[@tecnaman9097]

If the customer was told it was a faulty fuel injector causing the misfire after he/she had paid for a cylinder head r&r and a new replacement ECU!!!!. Very expensive mistake by the original shop but a professional diagnosis on your part James. I wonder if they fessed up and ate it???

[@yas_goku]

tecnaman dam they just made money

[@Gazavich]

Brilliant diagnosis with propa tools 👏 👏 👏 👏

[@giannoschr]

Good job !!! Well done!! Please add some more videos

[@007tomcampbell6]

Great diagnostic knowledge 👏

[@colinfield7768]

Great demonstration of diagnostic and physical testing of the system. It's sad though that whoever did the compression test, didn't do a wet and dry test and even smell the oil on the dipstick for signs of over fuelling and washing of the oil off the cylinder bore causing a drop in pressure. I'm an old school mechanic with modern Skills but I always tell modern technicians to NEVER forget the basics. Eyes, ears and a nose were around long before diagnostic machines!

[@steveguest8028]

Excellent diagnostics James but why on earth would the previous garage have removed the cylinder head when the problem obviously wasn't compression related ?....My only possible thoughts are that the excess fuel in cylinder 4 had caused bore wash.

[@PaulC1980]

Very thorough diagnosis. How did someone not check that before removing the head?.nice work and please keep videos coming.thanks

[@rectify2003]

Poor customers often have to pay for previous people who prey on them, due to lack of knowledge Thats why its so hard to find honest mechanics, and dealers are part of the problem. Even tho this guy diagnosed the problem, which was great, quite a bit is showmanship for the camera.

[@duanedonaldson2262]

If you have an Amp Clamp to get an amp waveform, you will be able to see the fuel injector pintle opening movement, great video, thanks so much.

[@ddmoldforgeworkshops5746]

Nicely done with great equipment....... tbh we would have changed the injector into another cylinder to see if the misfire moves well before removing the cylinder head.

[@tonykb2193]

I have a mk4 polo 9n bby and it has the intermittent no start (code 01314) but when it does start it runs just like that and throttle pedal response is delayed and it cuts off cyl 3. First I'll check easy stuff like dry joints in relays and cheap to do things like that, had a few wobbly relay pins in my time that have been less than a joy to diagnose. I have the same gas analyser, great little unit.

[@CHIBA280CRV]

Fantastic diagnosis, wish I was able to see the pico scope analysis, camera was too far ..

[@markferraro5250]

great video mr Dillon is there also a way to put a pico WPS500 into the fuel rail a dual trace a fuel injector on one signal and the pressure drops on the other channel? I would think the #4 injector drop would stick out like a sore thumb thanks again mark ferraro

[@Howardtripper]

cant see a thing you should zoom in so we can see

[@rxpx69]

Great video!!

[@alanpassat6759]

what fault codes were stored? Instead of an exhaust gas analyser, could lambda from the ECU be used instead?

[@nickpritchard7130]

Great vid. Very informative.Had to be a clever brit to post this Information. Big Thankyou.

[@WorldEagleKW]

Good video!

[@nickpritchard7130]

Hi JAMES, I recently purchased a 2013 vw jetta 1.4L Turbo Sedan from an auction here in Western Australia. It had a PO3O4 Code come up on my diagnostic tool. This indicated that Cyl 4 had a miss fire. I changed all the plugs and Coils. Still the slight miss was there. The car drives ok when driving round the streets here, but is rough on idle. I completed a compression test and the results are as follows.. Cyl 1 110 Cyl 2 110 Cyl 3 110 Cyl 4 83 There is no smoke from the car exhaust. It has only travelled 114,000 Klms and is in good condition. Question: If No. 4 fuel injector was open, or faulty, would this effect the Compression Test.? I find it hard to believe that the valves or piston would be suspect on such a low mileage vehicle. I also checked for air leaks and blew out the air filter. I also checked the Air Intake manifold and found a small amount of engine oil inside.? Not sure why it was there. Anyway i was going to purchase and fit a new Injector to No. 4 Cyl. Do you think it is worth doing given the results of the compression test? If you can help with any of the above i would be very greatful. Kind Regards Nick Western Australia

[@derwenthotel]

Brilliant thanks

[@ruanstander9823]

Hi James, I've got a problem on my 2006 Volkswagen Polo 1.6 (9N3 model). Engine code is BAH. Every 4-5 seconds there's a shudder on the engine which is felt right through my seat inside the car. When the engine is hot or just done long distance traveling the shudder becomes worse, every 2-3 seconds. I've done all my research on common problems of those engines. One of those problems are either spark plug leads (HT leads) especially cylinder number 4 lead which is close to the gearbox and also the coil pack (distributor). I checked all my leads and they were good except lead number 3 because of corrosion. Bought 4 new leads from the dealer and that did not solve the problem. Had the MAP and throttle valve cleaned and the shudder still wont go away. Took it to the dealer and they diagnosed the problem as slightly low compression on cylinder number 4. It didn't make sense as no fault codes were found. Upon asking they mentioned it could be a piston ring failing or sticky valve. Other common problems are either the engine speed sensor or the lambda sensor (oxygen sensor). After looking at your video I'm more inclined to say it might be an injector even though I have poured in Wurth's injectorcure into the fuel tank which dampened the shudder slightly, but after working it out of the fuel system the shudder came back. Also my hydraulic lifters becomes louder when the engine is hotter. The bill from the agents just to open the engine and then to diagnose the problem in depth without fixing any problems will cost me an arm and leg. What would be your best advice and also do you know of any common problems (other then mine) on these engines (BAH) especially when it comes to shudders? Any advice will be helpful as I'm currently a student and cant afford to pay a huge amount for in-depth diagnostics. Thank you in advance

[@jenziie_olivia1384]

Misfire On A Single Cylinder Is Easy To nail. It is random misfire, that swap back and for to a single cylinder that is driving me crazy

[@billrimmer5596]

Very nice job!! I am in Los Angeles and enjoyed your video very much!! Do u look at the comments and reply? Hope so. Fantastic equipment!!

[@sara78130]

best teacher

[@kylebarry6520]

Nice equipment at your disposal . Wondering why you wouldn't use co readings and oxygen content for direction in missfire diagnostics. The Hc readings start to drop as the catalist lights off pre cat sampling is always best but can be a pain in the ass to acess on newer vehicle's overall good vid

[@screwsnutsandbolts]

Great videos. Subscribed :)

[@stuartlloyd1035]

Wow amazing have the same car but it’s a 2004 and it’s doing the same thing so will just replace them all to be safe as don’t have the special tools to find out witch one it is thank you so much

[@alanjardine7527]

hi, issue with my 2016 skoda 1.2 epc warning, Seams like Arnold cark has said the diagnosis is that 2 injectors have failed which i think is nonsense, so 2 new injectors later Arnold clark still say there is a fault, . Do injectors fail at the same time when the car has done 28.000 and just out of warranty. Is it possible to swap injectors without coding to rule them out. ?

[@jenziie_olivia1384]

I have tried to scope my jnjectors, and see no abnormal pattern. That injector machine would not do me any good because I get a random misfire, that sometimes become no.6 I have swapped coils, injectors, none help, I have done everything, I mean everything, compression, vacuum etc

[@joemalone9380]

very helpful.

[@philaningobese1602]

I have been looking for this kind of clarity and that what my car is doing, I have tried all other things plugs egnition coil still not resolved but now I know the real reason

[@danman9017]

in the diagnostic tool .there no injector test?

[@sami25002002]

Thanks alot

[@KINGCALLO]

Couldn't you just swap around the injectors and clear codes then check codes once its starts misifiring to see if the cylinder misfire changes. Buying an ecu before that is insane.

[@davidsten780616]

it så easy test to check sparkplugs,coil and injektors.. i just changes with another cylinder first plug then coil and last injektors if the fault change cylinder than you know the problemet.. its the first thing you test...

[@ncooper8438]

Op doesn't say whether the engine exhibited the roughness only at idle, was it also running rough at speed?

[@suri2011]

It's look like weak pintle spring.but rather you do this big test,you can confirm this with labscope connecting amp meter

[@kas3214]

Also had EPC light on occasionally

[@JOHNPHUFNAGEL]

Thank you this video is very informative.

[@mikeford6611]

nice vid I have a missfire to mk 4 1.6 16v AZD engine trying the basics maff egr coils plugs thinking maybe injectors now. Its weird it will start say 3 times a day butthen it wont start maybe once the engines hot but even like 3 hours later still no start have to leave it till the next day. Any ideas?

[@Accarvd]

+mike ford probably you have solved it already but I would check the spark plugs!

[@felixmpho2085]

I am seating with the same problem…insurance through its mechanic have replaced a damaged engine with a new one due to water damage…so it have been misfiring ever!!!

[@whatthehell3949]

professional

[@jamiesimpson1786]

I wonder how the bill was explained. Compression issue was probably because of bore wash.

[@felixmpho2085]

Why the thump down? If anyone is having better info please share

[@robinkumar8689]

Hey dude well done for such knowledge But will you please suggest me because I m facing a problem with my VW petrol 4 cylinder engine . If I m driving it in 4th gear and as soon as I reduces its speed to 40 kmph and again increases speed in same gear than it feels heavy misfire Please help me

[@mikeford6611]

ps. when it does starts its missing on cylinder 3.

[@petecurran3995]

Phenomenal! All the work on head and ecu etc. I have a similar issue with a 1.4 tsi CAVE and after swapping coil and plug with neighbouring cylinder, the problem stayed put and I'll be chasing no.3 injector next. No Pico or quantifier though, that's all fine equpt. 👍🏻

[@ncooper8438]

How does the ECU know which 'cylinder' is defective?

[@Adamasher8888]

Hi does the misfiring go away when you press the accelerator? I’ve got a polo 1.4 2005 petrol and it shakes on idle but as you put some acceleration it goes away ... is it the fuel injector or an electronic issue?? You’re help will be appreciated 🙏🏽

[@RumelM]

Did you solve this? I have exact same issue

[@Adamasher8888]

@@RumelM no not yet some say it could be valve but way to diagnose is compression test on each spark plug inlet by removing spark plugs. Or it could be injector issue. Not sure what it is hope someone can help.

[@Adamasher8888]

@@RumelM not yet

[@mrjburton]

No way, talk about a spoiler I really wanted to see if it solved the problem grrrrrr, it was just getting good.

[@michaelhawthorne8696]

I agree, the video detail in the diagnostic was limited but I was able to follow (Just), I wonder though why the first people to see this didn't think "Injector fault"... Having said that, a great insight to the tools needed to get a car on the road these days. Gone are the days when all you needed was a battery and bulb strobe light to sort everything out. Gives me some insight as to why modern cars (While supposedly more reliable) cost so much to repair.

[@sphiwemasanabo2320]

My polo vivo is having the same problem

[@JackKello]

I've put up a video on my page please check it out. I've got random misfires on all cylinders. What could the cause be? Spark plugs are new. The car is a VW GOLF 1.8TSI 2010. Fuel pump is OK.

[@auzziemax]

Carbon build up due using unleaded rather than super unleaded

[@centralintelligenceagency9003]

Man, I'd be pissed. That customer paid out of his ass to get a valve job and an ECU swap he didn't need, only for the problem being an injector. Kind of hard to not accuse that other garage of malicious practice when one of the first suspects in problems with one cylinder should be the injectors.

[@vedranbuterin2595]

I knew it!!! It must be clogged fuel injector!

[@jenziie_olivia1384]

Swapping injectors is even too much work. You have to pull it out and put it back together. I just scope it, and know right away it's badm

[@sluuter]

Where I get this tool with one u use to take of airflow pipe clmap 🤤😛😛

[@AgentOffice]

wow car ekg!

[@kas3214]

My car is misfiring on cylinder 2. I’ve got a vw polo 1.4 TSI blue GT 63 plate. It drinks a lot of fuel it’s a joke

[@penjejakarus5033]

I encounter the same problems with Tiguan 2.0 .misfire..the source of the problem are injector cover clogged with carbon..i just clean the mesh metal Infront of the injector..problem solved

[@mukeshghimire6169]

I'm getting misfires on my Tiguan too. All possible causes ruled out and guessing on carbon build up. Did you clean it yourself or did you have to go to a mechanic?

[@neilw5198]

I always missfire with a headjob

[@ndishavekhuphani8211]

I am requesting your telephone to talk to you my vehicle was renewed engine after does not want to start I buy starter and does not start need electrician to assist

[@benzman113]

super market fuels/ & wrong oils used, see this all day long, use Shell v power fuel & branded oils you get what you pay for.

[@michaelhawthorne8696]

benzman 113: I agree totaly.... I was talking to a guy who was refueling a service station ,many years ago and he told me about the benefits of Shell and their additives.... I try all the time to put shell in but occasionall (Finance permitting) I have to sucomb to the supermarket price draw. If the result of penny pinching is this video then you will lose out 2 to 3 fold. I would love to use V power all the time but it costs too much to use it that often. I'm Diesel now

[@nsoper19]

@@michaelhawthorne8696 Interestingly I have a mate who works at the Fawley Refinery and he says the exact opposite lol. That the chemicals in the V-power stuff are such low concentrations that they don't really do that much. He said it was better to use some Redex or fuel cleaner every once in a while to keep things tip top.

[@alenallen7274]

A ukoliko ne bude niti ovo probajte sa ovim cam follower.nalazi se ispod pumpe visokog pritiska.znam iz iskustva jer su me majstori izuli naprosto.bacio sam 1000 € radi jebenih 40 €.najveci uzrok sto izbacuje greske miserfire.

[@InverJaze]

VW much easier to work on injector rails than Renault or Peugeot

[@666papcio]

lol WV no thx

[@20momina]

You,talk too much man. How did you take the engine cover off