Make a donation

Author Topic: Misfire with no EML  (Read 7799 times)

Offline andyy

  • Just Arrived
  • **
  • Thank You
  • -Given: 1
  • -Receive: 1
  • Posts: 24
Misfire with no EML
« on: October 31, 2016, 02:01:39 pm »
I've recently developed a misfire from 3500 rpm onwards.. The car runs absolutely fine at idle and in all gears up to 3500 rpm.

At first I thought it was a bad batch of fuel (Momentum 99) but I've ruled that out due to the misfire only under load. I've got a Evoms intake, R8 coil pack and new spark plugs on order so hopefully this will resolve the issue.

There is no EML on and I have scanned using an obd2 scanner via Torque. It's booked in at a garage for a VCDS scan but if anyone has had similar issues or can offer advice it would be appreciated.

Cheers,

Offline AJP

  • Global Moderator
  • Just look at my post count
  • *
  • Thank You
  • -Given: 392
  • -Receive: 316
  • Posts: 3212
Re: Misfire with no EML
« Reply #1 on: October 31, 2016, 07:59:46 pm »
I've recently developed a misfire from 3500 rpm onwards.. The car runs absolutely fine at idle and in all gears up to 3500 rpm.

At first I thought it was a bad batch of fuel (Momentum 99) but I've ruled that out due to the misfire only under load. I've got a Evoms intake, R8 coil pack and new spark plugs on order so hopefully this will resolve the issue.

There is no EML on and I have scanned using an obd2 scanner via Torque. It's booked in at a garage for a VCDS scan but if anyone has had similar issues or can offer advice it would be appreciated.

Cheers,
I take it there weren't any codes stored when you scanned it with Torque? Definitely get it scanned with VCDS, it's half the battle won.

Ideally you'd get a code showing a misfire on a specific cylinder, say cylinder 2. Then swap the plug on 2 with the plug on 3. Clear the codes. Get it to misfire again. Scan. If the misfire has moved to cylinder 3 it's therefore almost certainly a bad plug.

If the misfire stays on cylinder 2, do the same thing but with the coils. Swap coils 2 & 3 over, clear codes, misfire, scan, misfire on 3 points to a bad coil.

If it still stays on cylinder 2 after you've done all that, it could point to a bad injector, or a mechanical fault with the engine itself. A compression test will help.

I went through all of this and got as far as concluding it was likely to be a bad injector causing my misfires. I bought a used set off a breaker which I had refurbed by mrinjector. Seems to have done the trick. You might just be able to bang a single used injector in and fix the misfire; I figured a refurbed set of 4 made more sense to me.

Hopefully it's only a coil or plug causing your misfire though. That's much cheaper than injectors or worse. Make sure you try swapping things round before you fit any new parts - you'll know where the issue lies doing it that way. You could just fit four new plugs and four new coils but you wouldn't know exactly what failed and what you're fixing.

Offline andyy

  • Just Arrived
  • **
  • Thank You
  • -Given: 1
  • -Receive: 1
  • Posts: 24
Re: Misfire with no EML
« Reply #2 on: November 01, 2016, 11:16:59 am »
I've recently developed a misfire from 3500 rpm onwards.. The car runs absolutely fine at idle and in all gears up to 3500 rpm.

At first I thought it was a bad batch of fuel (Momentum 99) but I've ruled that out due to the misfire only under load. I've got a Evoms intake, R8 coil pack and new spark plugs on order so hopefully this will resolve the issue.

There is no EML on and I have scanned using an obd2 scanner via Torque. It's booked in at a garage for a VCDS scan but if anyone has had similar issues or can offer advice it would be appreciated.

Cheers,
I take it there weren't any codes stored when you scanned it with Torque? Definitely get it scanned with VCDS, it's half the battle won.

Ideally you'd get a code showing a misfire on a specific cylinder, say cylinder 2. Then swap the plug on 2 with the plug on 3. Clear the codes. Get it to misfire again. Scan. If the misfire has moved to cylinder 3 it's therefore almost certainly a bad plug.

If the misfire stays on cylinder 2, do the same thing but with the coils. Swap coils 2 & 3 over, clear codes, misfire, scan, misfire on 3 points to a bad coil.

If it still stays on cylinder 2 after you've done all that, it could point to a bad injector, or a mechanical fault with the engine itself. A compression test will help.

I went through all of this and got as far as concluding it was likely to be a bad injector causing my misfires. I bought a used set off a breaker which I had refurbed by mrinjector. Seems to have done the trick. You might just be able to bang a single used injector in and fix the misfire; I figured a refurbed set of 4 made more sense to me.

Hopefully it's only a coil or plug causing your misfire though. That's much cheaper than injectors or worse. Make sure you try swapping things round before you fit any new parts - you'll know where the issue lies doing it that way. You could just fit four new plugs and four new coils but you wouldn't know exactly what failed and what you're fixing.

Thanks for the reply.

No, no codes or codes pending when scanned via Torque. It's going in for a VCDS scan this week so hopefully I will get to the bottom of it!

I'm glad you got to the bottom of your issue. Did you have an EML light on at all? I don't even get a flash when it's misfiring.

MPG is absolutely fine.. in fact as I have to stay below 3500 rpm / 60 mph I'm getting around 35 to the gallon!! No smell of fuel or anything.. which has me thinking it''s *hopefully* nothing major!

I will let you know how I get on after the VCDS scan.

Only plus side is that my car is will have all the hardware for stage 1+ :D
 

Offline AJP

  • Global Moderator
  • Just look at my post count
  • *
  • Thank You
  • -Given: 392
  • -Receive: 316
  • Posts: 3212
Re: Misfire with no EML
« Reply #3 on: November 01, 2016, 11:35:02 am »
I've recently developed a misfire from 3500 rpm onwards.. The car runs absolutely fine at idle and in all gears up to 3500 rpm.

At first I thought it was a bad batch of fuel (Momentum 99) but I've ruled that out due to the misfire only under load. I've got a Evoms intake, R8 coil pack and new spark plugs on order so hopefully this will resolve the issue.

There is no EML on and I have scanned using an obd2 scanner via Torque. It's booked in at a garage for a VCDS scan but if anyone has had similar issues or can offer advice it would be appreciated.

Cheers,
I take it there weren't any codes stored when you scanned it with Torque? Definitely get it scanned with VCDS, it's half the battle won.

Ideally you'd get a code showing a misfire on a specific cylinder, say cylinder 2. Then swap the plug on 2 with the plug on 3. Clear the codes. Get it to misfire again. Scan. If the misfire has moved to cylinder 3 it's therefore almost certainly a bad plug.

If the misfire stays on cylinder 2, do the same thing but with the coils. Swap coils 2 & 3 over, clear codes, misfire, scan, misfire on 3 points to a bad coil.

If it still stays on cylinder 2 after you've done all that, it could point to a bad injector, or a mechanical fault with the engine itself. A compression test will help.

I went through all of this and got as far as concluding it was likely to be a bad injector causing my misfires. I bought a used set off a breaker which I had refurbed by mrinjector. Seems to have done the trick. You might just be able to bang a single used injector in and fix the misfire; I figured a refurbed set of 4 made more sense to me.

Hopefully it's only a coil or plug causing your misfire though. That's much cheaper than injectors or worse. Make sure you try swapping things round before you fit any new parts - you'll know where the issue lies doing it that way. You could just fit four new plugs and four new coils but you wouldn't know exactly what failed and what you're fixing.

Thanks for the reply.

No, no codes or codes pending when scanned via Torque. It's going in for a VCDS scan this week so hopefully I will get to the bottom of it!

I'm glad you got to the bottom of your issue. Did you have an EML light on at all? I don't even get a flash when it's misfiring.

MPG is absolutely fine.. in fact as I have to stay below 3500 rpm / 60 mph I'm getting around 35 to the gallon!! No smell of fuel or anything.. which has me thinking it''s *hopefully* nothing major!

I will let you know how I get on after the VCDS scan.

Only plus side is that my car is will have all the hardware for stage 1+ :D
I eventually got a warning light, yes. At first it just misfired, then as the misfire got heavier the light would flash while it was misfiring, then the light stayed on constantly.

I think the ECU has to detect a certain amount of misfires before a fault code is stored. If the light is on you'll likely have a code, but if it isn't there's a fair chance you won't. There's a case for driving it until it stores a code so you have a better starting point for diagnosing the fault, but if the misfire is causing things to go lean it might not be advisable; maybe just fitting 4 new plugs and/or coils is a better option (after you've tried data logging).

When I first went about tackling mine I put in a set of new R8 coils and it 'fixed' the misfire, but only for a day. After 24 hours the misfire came back, and so I investigated further and ended up fitting a set of refurbed injectors. It's been running well for a good few weeks now so I'm confident it's done the trick.

If a scan with VCDS doesn't show any codes the next best thing is live data logging with VCDS. Basically you'll drive around with the laptop plugged in and any misfires (that aren't necessarily logged as fault codes) will show up in real time. This data can be saved as a file for reference. It's just a case of logging the correct parameters. In my case when I did a logging session the car decided to behave impeccably and didn't misfire once, so I was still none the wiser. At this point I was already on new plugs and coils so I turned my attention to the injectors.


Offline gttdigoof

  • Always Involved
  • ****
  • Thank You
  • -Given: 2
  • -Receive: 2
  • Posts: 116
    • bf1systems
    • Email
  • My Ride: http://www.mk5golfgti.co.uk/forum/index.php/topic,104209.0.html
Re: Misfire with no EML
« Reply #4 on: November 01, 2016, 01:09:09 pm »
The misfire on mine never showed, I believe you can deactivate misfire DTCs

I had to monitor the misfires manually (cant remember which measuring blocks to watch) although mine was easier due it being at low idle

Mine was caused by the injectors



 Mk6 R :)

Offline andyy

  • Just Arrived
  • **
  • Thank You
  • -Given: 1
  • -Receive: 1
  • Posts: 24
Re: Misfire with no EML
« Reply #5 on: November 01, 2016, 01:16:44 pm »
The bloke I'm taking my R to will be able to diagnose it. I'm hoping it's not injectors.. on a 4yr old R that's been ran on premium fuel and fsh and some shouldn't have an issue.. I'd hope not anyway!

Offline gttdigoof

  • Always Involved
  • ****
  • Thank You
  • -Given: 2
  • -Receive: 2
  • Posts: 116
    • bf1systems
    • Email
  • My Ride: http://www.mk5golfgti.co.uk/forum/index.php/topic,104209.0.html
Re: Misfire with no EML
« Reply #6 on: November 01, 2016, 01:24:29 pm »



 Mk6 R :)

Offline andyy

  • Just Arrived
  • **
  • Thank You
  • -Given: 1
  • -Receive: 1
  • Posts: 24
Re: Misfire with no EML
« Reply #7 on: November 01, 2016, 04:55:26 pm »
I've just changed the coil pack to R8 ones and the misfire has gone! I will keep an eye on it and if it returns I will get it booked in for a full diagnosis :)

Offline grey golfster

  • Always Involved
  • ****
  • Thank You
  • -Given: 79
  • -Receive: 34
  • Posts: 460
  • Edition 30 # 993; Stage 2 n a bit....
Re: Misfire with no EML
« Reply #8 on: November 01, 2016, 07:16:45 pm »
The bloke I'm taking my R to will be able to diagnose it. I'm hoping it's not injectors.. on a 4yr old R that's been ran on premium fuel and fsh and some shouldn't have an issue.. I'd hope not anyway!

4 yo R...so not one of these then?

Watch "Problems with my 2017 Golf R already?" on YouTube   injectors changed under warrantee...




Offline andyy

  • Just Arrived
  • **
  • Thank You
  • -Given: 1
  • -Receive: 1
  • Posts: 24
Re: Misfire with no EML
« Reply #9 on: November 01, 2016, 07:56:34 pm »
The bloke I'm taking my R to will be able to diagnose it. I'm hoping it's not injectors.. on a 4yr old R that's been ran on premium fuel and fsh and some shouldn't have an issue.. I'd hope not anyway!

4 yo R...so not one of these then?

Watch "Problems with my 2017 Golf R already?" on YouTube   injectors changed under warrantee...



No its not a mk7.. It's a shame you're having issues! At least it's all covered under warranty and I guess you can still reject it if more issues arise.. especially if it's spending weeks on end at VW!

Offline gttdigoof

  • Always Involved
  • ****
  • Thank You
  • -Given: 2
  • -Receive: 2
  • Posts: 116
    • bf1systems
    • Email
  • My Ride: http://www.mk5golfgti.co.uk/forum/index.php/topic,104209.0.html
Re: Misfire with no EML
« Reply #10 on: November 01, 2016, 08:03:40 pm »
glad you got it sorted



 Mk6 R :)

Offline andyy

  • Just Arrived
  • **
  • Thank You
  • -Given: 1
  • -Receive: 1
  • Posts: 24
Re: Misfire with no EML
« Reply #11 on: November 01, 2016, 08:08:34 pm »
glad you got it sorted
Thanks, hopefully that's the issue resolved! although after reading a comment above after changing the coils it came back after 24 hours. I guess I will just have to wait and see!

Offline AJP

  • Global Moderator
  • Just look at my post count
  • *
  • Thank You
  • -Given: 392
  • -Receive: 316
  • Posts: 3212
Re: Misfire with no EML
« Reply #12 on: November 02, 2016, 12:51:44 pm »
glad you got it sorted
Thanks, hopefully that's the issue resolved! although after reading a comment above after changing the coils it came back after 24 hours. I guess I will just have to wait and see!
Fingers crossed. Just keep an eye on it - mine seemed easier to 'upset' when it was just up to temp from cold. Try loads of varied driving and hopefully it's done the trick.

Offline Jambo1994

  • Can't Read PM's Yet!
  • *
  • Thank You
  • -Given: 0
  • -Receive: 0
  • Posts: 4
    • Email
Re: Misfire with no EML
« Reply #13 on: November 06, 2016, 01:51:34 pm »
I had a similar issue when I was on full throttle at high speed, changed plugs and was sorted instantly  :happy2:

Offline andyy

  • Just Arrived
  • **
  • Thank You
  • -Given: 1
  • -Receive: 1
  • Posts: 24
Re: Misfire with no EML
« Reply #14 on: November 06, 2016, 04:40:56 pm »
Luckily mine was the coil packs. It was still running a bit lumpy and it didn't feel 100% until I filled up with Vpower earlier today and now it's near perfect again! (I must have had a bad batch of Momentum 99) aswell as a shot coil.