Yet..ANOTHER!!!! Misfire question!?!?

[jdell88]

Ok, so straight up, i know its beem asked many many time before but i believe every case is differen.

Basics: changed out coil pack to r8, ngk plugs gapped to 0.028 or whatevwe it os, new air filter bg44k and bg carbon inake clean...still a miss!

The engine is a cndnc and the car is a4 q avant.
The mis is between 2k and 3k rpm under "mild" load, around half to 3/4 throttle. Maybe 1-3 audibly noticeable misfire within the range.
The previous had removed the the two left and right rear mufflers so could this be a back pressure issue as this is same range the boost comes ones on? Or could it be something more?

Cheers in advance and hello from aus :)

[BlownOne]

If you've changed everything you listed under basics, then I would say possibly a blown head gasket. As soon as boost comes on it gets herky jerky and misfires cause it's lifting the head or drinking coolant.

Will

[AudiTechS4]

you know its missing because what ? cel , your logging , or your best guess ?

[jdell88]

No cel and no longing as yet because i can seen to get the software to install on the laptop.
I know because i can hear and feel usually 2-3 "pops" or slight backfires. To me it feels like it could be running rich.

It doesnt get to "herky jerky" when boost comes on, its just abit hesitant with the possible misfire and then everythings sweet.

[nickskeeta]

What gas are you running?
My EPC light came on a couple weeks ago for a misfire under heavy 2nd gear load. It shut off as soon as I restarted my car. Searched online and noticed multiple people claiming bad fuel is a common problem for misfires on the B8 S4. I aways filled up with Arco (BP) 91 previously because of convenience and decided to fill it up with Shell V-Power 91 instead and the car runs noticeable smoother and have yet to throw a code since

[jdell88]

I was also running BP 98 ron and just put a tank of V-Power so i will see if there is any improvement.

Thanks for your input.

[dizzlesizzle]

I only use shell 93 nitro and runs perfect. i haven't even changed my plugs yet at 61K

[jdell88]

Problem sorted! New MAF on the way

[Mat@1975]

Problem sorted! New MAF on the way

Hello

MAF ??

Our S4 don't have MAF....


BR

Mat

[doug97gxe]

Hello

MAF ??

Our S4 don't have MAF....


BR

Mat

LOL

[jdell88]

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[Mat@1975]

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OK, i realized that you have an A4, not a S4. Maybe you did not post in the good section...

Which engine ? it's certainly not a 3.0L TFSI of the S4 since the engine is not MAF based but MAP based.

By the way, MaF are a weak part in VW engines.

Hope this will slve your issue.

BR

Mat

[jdell88]

Thanks mat!
Im not sure which this is in to be completely honest. Kind of new to forums and audis.

Its a 2.0 tfsi cdnc in a b8 avant quattro.



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[jdell88]

But yes, disconnected and its running fine so just waiting on the part.
Now i have esp and e brake lights so need to change the codes with a VAG or something if i read correctly elsewhere??

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[doug97gxe]

Thanks mat!
Im not sure which this is in to be completely honest. Kind of new to forums and audis.

Its a 2.0 tfsi cdnc in a b8 avant quattro.



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oh here you go http://www.audizine.com/forum/forumdisplay.php/97-B8-A4