1.8T! Single Cylinder Misfire: Cylinder 2 Help!!

[b6.brandonnn]

Hey guys, you might remember me when my car was misfiring terribly. So i been having a problem where on cylinder 2 it would have a very slight misfire on and off again, it seems to happen more often when the engine is cold and at idle. After driving it for like 20 minutes it kind of slightly misfires every now and then.
Car is driveable and i only get the misfire code when its at idle and never while im driving.

Heres whats been done:
Brand new- injectors, spark plugs, coilpacks, coilpack harness, injector harness, cleaned maf literally was done like a month ago

Car is 119,000 miles
Engine Code AMB
Tuned By motoza stage 1



Let me know what you guys think, itd be much appreciated!!

[Mike Tries]

I know you say it has new coils, but let's start by swapping coil 2 with another one to see if the problem moves with the coil (defective new coil) or stays put. That would be an easy win.

How are the plug gaps? Make sure they're correct. Also... people more knowledgeable here than I am might want to know what kind of spark plugs you put in because apparently these engines can be finicky.

While you're checking the plugs, maybe swap the plug from cylinder 2 to another cylinder (after testing moving the coils around) to see if the problem follows the plug.

You might want to try swapping back to the stock tune, too, if it's not too much trouble. See if that does it. (I'm trying to go in order of easiest/quickest to hardest in the order here.)

If the problem persists on cylinder 2, the next step is to make sure the coil pack harness was done right. Are the connections secure? You picked up that replacement kit for which you have to cut the wires and pin them, right? Test those connections to make sure they're secure.

Does your car consume any coolant? When you took the plugs out, did they come out OK, or were any stuck? AMB heads, as I found out, are a bit fragile. Don't raise alarm bells yet, but just keep an eye on some of the tell-tale signs of head problems.

[b6.brandonnn]

Okay ill swap the coilpacks around, i also have had the same ngk spark plugs and never had problems with it, so for a new pair i wouldnt think it would change much.
How do i swap back to the the stock tune?

[kwilson]

Which coil pack harness did you use?

[b6.brandonnn]

ecs

[EuroxS4]

Could be issue with ignition coil harness,the coil itself of plugs. Worst case scenario It could be a cracked cylinder head or valve face.

[Gin+]

Pull plug and check for wet cylinder (coolant) in the morning with flashlight if the other suggestions don't work out.

[kwilson]

ecs

There you go. Jiggle the connector (push it the wires in more) and see if the misfires go away. Same thing happened to me after repairing my son's coil harness. A few months after the repair, the wires started coming loose. I ended up replacing it with the USP harness.

[Mike Tries]

Okay ill swap the coilpacks around, i also have had the same ngk spark plugs and never had problems with it, so for a new pair i wouldnt think it would change much.
How do i swap back to the the stock tune?

I would just check the gap on the plug and compare it to spec (and maybe to the other plugs). They come pre-gapped, but maybe it got dinged and the gap closed or something. Swapping it with another plug might also identify if the plug is having issues.

Swapping the tune... I'm sorry, but I can't help you much here. If you put it on there, then I would imagine the programmer thingy that you plugged in to make the swap happen in the first place would allow you to reverse it. Sorry that I can't be more help here--I'm running a community-derived tune that I threw onto my car with my laptop and swapping it is pretty straight-forward by just using the laptop. If your car came tuned, and you don't have the tune thingy, I would revisit this only after you try all other things.

[Mike Tries]

Pull plug and check for wet cylinder (coolant) in the morning with flashlight if the other suggestions don't work out.

Yes, this. This is how I figured out my AMB head was cracked (the stuck spark plug might have been another indicator). If it looks like it rained in one or more of your cylinders several hours after shutting the car off, then coolant is possibly/probably leaking in through cracks in the head. Running the car at idle, the coolant could be pouring in fast enough to extinguish combustion. Higher speeds would burn off the coolant quickly enough that you don't have the problem.

[EuroxS4]

ECS has got to have the worst harness repair kit on the market, you are adding another failure point/loose connection to the original harness. Factory repair harness was the best which is what USP uses IIRC.

[b6.brandonnn]

if it was cracked, wouldn’t i have coolant loss? i’ve had pretty much the same level of coolant all throughout.

[Mike Tries]

if it was cracked, wouldn’t i have coolant loss? i’ve had pretty much the same level of coolant all throughout.

Yeah, you would be losing coolant. It is good that you're not.

[b6.brandonnn]

So ive swapped the coilpacks around and spark plugs, drove today and got another misfire code there on cylinder 2. i think my next step would be to swap the injectors around.

[EuroxS4]

So ive swapped the coilpacks around and spark plugs, drove today and got another misfire code there on cylinder 2. i think my next step would be to swap the injectors around.

I would check the harness for ignition coil. Normally wires break under the rubber boot.

[Mike Tries]

Well. Reopening this discussion for a bit... I installed my new coils this weekend, and in the process of swapping out a few harness connectors that I broke, I had a back-away-slowly moment. I pulled the rubber boot back and discovered that all four wires going to at least the number 2 ignition coil had ripped up insulation and exposed copper wire. Seeing as how I had no issues with cylinder 2, I thought it prudent to put the rubber boot back exactly where I found it, reconnect everything to the new coils, and just pretend we weren't here. Maybe I wasn't there. Maybe it was a dream. Seems to be working out OK. In the meantime, kwilson and EuroxS4, thanks for the tip about the USP harness. I'll order one today.

b6.brandonnn, did you ever sort your misfire out?

[Cybersombosis]

At the very least put some black tape in between them to isolate the wires. Even just a strip is better than bare wire.

[AvantNoir]

I have a USP Motorsports Coil Pack Harness for sale at a discount:
https://www.audizine.com/forum/showt...placement-1-8T

[Cybersombosis]

We actually had a coil shoot flames out the rubber boot once. I suspect something flammable like WD-40 or parts cleaner got in and ignited from the short from the expose wires.

[Mike Tries]

We actually had a coil shoot flames out the rubber boot once. I suspect something flammable like WD-40 or parts cleaner got in and ignited from the short from the expose wires.

Cool.

[Mike Tries]

I have a USP Motorsports Coil Pack Harness for sale at a discount:
https://www.audizine.com/forum/showt...placement-1-8T

Oh. Yeah, I saw your PM about the other thing before I made my way back here. You have the pins and stuff, too, right? I assume so, but I couldn't tell with the picture, and I don't remember what the kit is supposed to come with. I'll PM you back in a bit.

[BumblebVR6]

Oh. Yeah, I saw your PM about the other thing before I made my way back here. You have the pins and stuff, too, right? I assume so, but I couldn't tell with the picture, and I don't remember what the kit is supposed to come with. I'll PM you back in a bit.

It comes pinned, ready to install.

[AvantNoir]

Mike Tries grabbed it. Shipping today.

[Mike Tries]

My YouTube thing is going to go from Mike Tries Motorsports to Mike Tries Keeping a Tired Old Audi Running for Just a Bit Longer.

[Turbo510]

At the very least put some black tape in between them to isolate the wires. Even just a strip is better than bare wire.

I found that wires at a knock sensor connector had flaked off some insulation. After flexing exposed copper away from adjacent exposed copper, I encased them all in a blob of clear Silicone. Not beautiful, but also hard to see unless you are looking for it.