Persistent Misfire: Cylinder 5???

[rocksarntpeople]

Title says it all...persistent misfire code on cylinder 5 and just trying to figure out why...below is the list of the things I have replaced in the order they were done and mileage...stock tune and car currently has 61,500 miles:

Plugs: OEM - 59500
Coils: OEM Eldor - 59500
Walnut Blasting: 59800
Replace all Oil Gaskets (oil filter housing, valve cover, oil pan, front and rear main) Coolant, Oil and Filter: 60000
Full OEM Turbo Replacement all lines, etc: 60500
PCV and Catch Can: 60500
VRSF Charge Pipe and Tial BOV: 60500
6 OEM Index 12 Injectors/Decouplers: 61000
Both Precat O2 sensors: 61500

**Update: After having gone through most of the advice in this post and moving plus/coils I followed the write up of how to clear adaptations in ISTA /D and that seems to have solved most of the problem, However...the misfires/stumbling still show during a cold start and occasionally while driving but NO CODES are thrown.

I have ordered 6 new BMW OE spark plugs and will see if this helps

**replaced the plugs with OE BMW plugs and now it seems like the cold start related misses are a bit worse and after running the car for a while, the idle jumps up to 800 RPMs**

***Also of note: my original number 6 injector gave me a hell of a time coming out and was covered in soot...perhaps the new one didn't seal properly because of soot in the bore? Can provide pictures if it would help.

***Edit: 1/26/2017: Erratic idle continues, threw a code for DMTL: 2A17...seems like this thing just has a never ending list of issues...any more things I should check or be mindful of?

***Edit: Not sure if its related, but I did replace all the vacuum lines and O-Rings for the intercooler and charge pipe...for now things seem to be normal with the occasional hiccup but back to no codes being thrown...my next course of action is to replace the stock intercooler and piping altogether and replace the boost solenoids and retune with MHD and see if things mellow out

[Matticus91]

Was the issue happening before all of the above were changed? Or was that all done as maintenance items and then the issue started?

[rocksarntpeople]

There have been random misfires and issues causing the need to do all of the above, now it just seems like its been isolated to cylinder 5...One thing to note, the current gen Eldor coils do not seem to fit as snugly as the original Bosch ones...has anyone else come across this???

[Matticus91]

Originally Posted by rocksarntpeople

There have been random misfires and issues causing the need to do all of the above, now it just seems like its been isolated to cylinder 5...One thing to note, the current gen Eldor coils do not seem to fit as snugly as the original Bosch ones...has anyone else come across this???

Ok this one's a bit above my pay grade I think. I will say that "new" doesn't necessarily mean "good" though. I've had plenty of stuff come DOA, so maybe try swapping coils and plugs from 5 to another cyl and see if that impacts anything.

[Gizmo135i]

Originally Posted by rocksarntpeople

There have been random misfires and issues causing the need to do all of the above, now it just seems like its been isolated to cylinder 5...One thing to note, the current gen Eldor coils do not seem to fit as snugly as the original Bosch ones...has anyone else come across this???

Try swapping the coils, also swap spark plugs... maybe put the cyl 5 coil in cylinder 1 and the plug in cyl 2 etc...

if it ends up being a plug consider getting plugs from Bmw as the bosh replacements are not the same plug and people have had issues with them.

[ianc]

What Gizmo said. Do not move plugs and coils at the same time; but do them one at a time so you can check each variable separately. Check the condition of #5 plug when you pull it. Black? Wet? Stinking of gas? If it has not been removed since the injectors were done, it could be fouled by your old (possibly leaky) injector.

If the misfires do not follow the plug\coil moves, then you may have a bad injector even if it has been replaced...

ianc

[Gizmo135i]

Also were the injector compensation values coded into the dme? That could make the car run weird if they weren't

[rocksarntpeople]

So an update....I coded the injectors properly and double checked last night while I moved the plug from cylinder 5 to cylinder 1 and the coil from cylinder 5 to cylinder 2...cleared the misfire code and everything seems ok minus a bit of stumbling at idle but no codes even under WOT...when I floor it in lower gears there is a slight hesitation so I filled up with 93 Sunoco and ran some Techron through it to see if it clears up...next step might be clean both MAP and TMAP sensors??


***Both Plugs and Coils looked normal...slight gas smell, but nothing out of the ordinary...not wet or black***

[1and1]

Were the injectors not coded properly prior to your changes last night?

[rocksarntpeople]

Originally Posted by 1and1

Were the injectors not coded properly prior to your changes last night?

Same coding...no changes were made...just double checked while I was in there.

[rocksarntpeople]

Another thought: What is the proper way to reset all the adaptations and learned values? INPA? ISTA? Flash a tune on it? Perhaps there are still some out of whack due to the various parts that were replaced?

[ianc]

You can clear adaptations with ISTA/D but it's not recommended when the injectors are replaced...

ianc

[Gizmo135i]

Originally Posted by rocksarntpeople

Another thought: What is the proper way to reset all the adaptations and learned values? INPA? ISTA? Flash a tune on it? Perhaps there are still some out of whack due to the various parts that were replaced?

Yes you should absolutely reset the adaptations after replacing injectors... on the newer cars ISTA even automatically prompts you to reset the fuel adaptations when you code the injectors. On the n54 I think you still have to go back out and reset them yourself, even on the latest versions of ISTA.

Even when you do a carbon blasting your supposed to reset them... pretty much anything you do that could affect the air/fuel ratio it can't hurt to reset adaptations.

Also a good idea would be to check for any intake or crankcase leaks. The valve covers are notorious for cracking around the ignition coil area, usually there will be some oil by the coils, and it could leak air into the crankcase and cause erratic idle etc... without faults.

Not saying it's your issue, but I wouldn't go too crazy hunting down misfires until you put Bmw factory plugs and coils in it. Honestly from what I have seen these cars really don't like aftermarket plugs or coils. even if it's "oem" that's not the same as original equipment or "oe"

Plugs should be torqued to 23nm... that's not a lot. if they were overtorqued they could also be damaged

[ianc]

Yes you should absolutely reset the adaptations after replacing injectors...

Interesting. My copy of Rheingold which I used to code my 135's injectors after I installed them recommended against it, saying that as a general rule, it should not be done after parts replacement...

ianc

[ianc]

You got me wondering, so I had to go take another look. Here's what I had seen before? Sorry about the stupid image stamp; I need to find another image hosting site...



ianc

[Gizmo135i]

Originally Posted by ianc

You got me wondering, so I had to go take another look. Here's what I had seen before? Sorry about the stupid image stamp; I need to find another image hosting site...



ianc

Well, I don't think that is ment to pertain to a repair or replacement of a part that can directly affect the mixture adaptations.

Also if you read those things in ISTA all day long you'll find a load of good info, but also some contradictions and misleading info here and there lol

Anyways on a side note DO NOT reset the equipment variations... only the adaptations.

[rocksarntpeople]

So is there a particular function in ISTA D that "resets adaptation values," and if so where can it be found? I tried looking yesterday and could not find it. On a side note, I flashed the Cobb stage 1 file onto the car and the only misfires that are present now seem to be at cold startup...pulls strong and true in all gears to redline? My guess is the reflash zeroed out most of these values??

[Gizmo135i]

Service functions; engine electronics; adjustment functions; reset adaptations and versions. (Something along those lines) and only reset adaptations, not versions... otherwise you might end up screwing up the coding in the car and it would need to be programmed

[chadillac2000]

Interested to see how this one turns out considering most of us battle misfire demons at some point or another along ownership.

While the injectors should be coded, yes, I wouldn't see that being the root cause of a misfire that has been there since the beginning. What codes are you currently throwing? Just a single misfire cylinder 5 code?

If you've recently replaced all those items and are still getting persistent misfires, one can only think it's ECU related. I'd grab a new coil for cylinder 5 (perhaps not the same brand if you're skeptical about the Eldors) before diving much deeper.

You've replaced all the common culprits of a misfire, so this sounds like you may have a specialized case on your hands. Either that or incorrect installation on some of those replacement parts. After seeing mechanics, BMW Certified and otherwise, work on the N54 engine, an error during installation is certainly a possibility.

Installing injectors with decouplers and coding them correctly is straightforward, but tons of people manage to mess this up.

Best of luck sir. Misfires are the worst.

[rocksarntpeople]

So another update on this baffling case: It seems that after the reflash (cobb stage 1) the misfires WHILE DRIVING are mostly gone, however there is still misfires on a cold start up and the occasional miss while driving however NO CODES are being thrown for anything...now Im completely stumped...

[chadillac2000]

Originally Posted by rocksarntpeople

So another update on this baffling case: It seems that after the reflash (cobb stage 1) the misfires WHILE DRIVING are mostly gone, however there is still misfires on a cold start up and the occasional miss while driving however NO CODES are being thrown for anything...now Im completely stumped...

When my injectors were on their way out I didn't get codes for the longest too. Progressively got worse to the point where it finally started throwing codes a few days later. I remember reading somewhere that an easy test is to throw it into a higher gear like 5th and roll into the throttle. Usually that will throw a code and give you some more insight.

Who performed all the repairs on your car listed in the original post?

[rocksarntpeople]

I did the injectors, plugs, coils, chargpipe, BOV and O2s...BMW and and indy BMW Performance shop did the rest