[oooseun]

Getting on the freeway, decided to WOT in manual mode. While easing off in 4th gear, the car starts to vibrate and Drivetrain malfunction lights up. I eventually get the car home driving slowly but noticed my exhaust was louder, the car stuttered and ran ROUGH at idle and stop lights, and would emit a puff of white smoke when I left a stop light/sign. I came to understand that this was unburnt fuel.

I let it rest for an hour, started it up and it was even worse. Took the longest I've ever seen it take to start and wasvery smelly (fuel).


Drivetrain Codes

140001 Fault: Misfiring, several cylinders: recognized Fuel injector is switched off
140010 Fault: Misfiring, several cylinders: recognized
140004 Fault: Misfiring, several cylinders: damaging exhaust gas

140410 Fault: Misfiring, Cylinder 4 recognized
140510 Fault: Misfiring, Cylinder 5 recognized
140610 Fault: Misfiring, Cylinder 6 recognized
140401 Fault: Misfiring, Cylinder 4 recognized; Fuel injector is switched off
140404 Fault: Misfiring, Cylinder 4 recognized; damaging exhaust gas
140501 Fault: Misfiring, Cylinder 5 recognized; Fuel injector is switched off
140601 Fault: Misfiring, Cylinder 6 recognized; Fuel injector is switched off



I was running this with a VSFR Chargepipe + Bootmod3 Stage 1 (91 Octane).
If it makes a difference, it's a little smoky in California right now.
52,000mi


From research, it looks like
1. Injectors
2. Coils
3. Spark plugs.

BMW replaced the spark plugs 2 months ago, so it's not likely to be that.
The interesting thing here is 3/6 Cylinders at the same time. I plan on reflashing to stock to reproduce. it seems like it would though, the car hasn't been programmed in ages.

Anyway, HELP? pls?

What should I be doing to further hunt the problem down?

[oooseun]

Update. Just flashed to stock.

Read codes, got a new one.

11AC02. This means something about the fuel pump.

I don't think that's necessarily the issue, however it felt like the car dumped a shitload of fuel in the cylinders, so much so that I started it for 90 seconds and didn't rev it but gas was basically dripping off the exhaust

Gonna do a battery reset and hope for the best

[Jnat]

Swapping components from known good cylinders to known bad cylinders can be a diagnostic step that makes sense. If the misfires follow a particular part swap then you have your answer. Swap a plug, swap a coil to start to see if the misfire follows. Injectors are more difficult in this sense so i'd out rule the plugs and coils to start.

[oooseun]

So (hopefully if i'm not reading this wrong, Good news!)

I Datalogged with BM3 and saw that only Cyl 6 was misfiring! This was a medium start, I never added throttle input just let it idle for a few seconds and turned it off when I started to smoke out my neighborhood.

Can someone more experienced take a look at the log/chart and see if they can tell anything?

Next Step is to swap Coil 6 and 1 or something. this is the easiest swap to do without any specialty tools (i.e. plug wrench attachment or injector removal tool).

The spark plug was replaced 2 months ago (by BMW) is there any reasonable chance this might still be an issue?

[oooseun]

Swapped the coils, Still seeing misfires on Cyl 6. This time, the car puffed a lot of smoke from the start and shut off after 16s.

Bootmod3 Log

[Jnat]

Fuel pump is not likely to be isolated to a cylinder, most likely would be multiple cylinders if not all.
Since it stayed in 6 i would swap a plug (wouldn't be the first bad plug ever installed) in there and see if it follows. If it does, problem solved, if it doesn't the last swap would an injector unfortunately. If it's none of that, it certainly gets more interesting.

[oooseun]

Got a bunch of things on the way, Injector removal tool, injectors, seals, spark plugs, thin walled spark plug removal tool, etc etc.

Yeah if it's not the spark plug or the injector then this just became a WHOLE big mess.

How likely is it that it's a bad fuel batch? I've seen this on the forums but I'm hesitant in my case as it wouldn't be localized to 1 Cyl right?

[Jnat]

From my experience, bad fuel from a misfire stand point would be multiple and even move around. Your're not experiencing that from what i see so not likely. Ask yourself why fuel would pick one cylinder? Again, i guess not impossible but i'm not sure i've seen that and or heard of that. If you get to a point where it's not the plug and it's not the injector i guess running the gas down or getting it out of your tank would be a last resort before it's gets uglier.

[XutvJet]

Sounds like the #6 injector is stuck open. If you have a catted DP, it may be toast now.

[tlum235i]

Is there any gas smell when the car is running? I may be wrong for your case, but I had to randomly replace one injector two years ago after a drivetrain error. I smelled some gas when it was stuttering/shaking.

[oooseun]

Alright! so it's Day 5 post Drivetrain Malfunction i have have good news.

I replaced the injector (EU6 variant), reset adaptations and started the car. I logged this start and here's what it looks like.

As you can see, there's initially misfires on Cyl-6 but I think that's the DME getting used to the new injector (I did not code it). I let it run idle for a few seconds then shut it off. IT still produces a SHIT ton of smoke, in fact I initially shut it off because I thought the smoke was coming from the engine but a second run showed it wasn't.

What is interesting to note (and why I think it's 'fixed') is the Target HPFP and actual are similar. you can see in the misfiring graphs, the target and actual are WAY off.


Strut brace, etc is still out and the car still produces A LOT of white smoke, but my guess is it's still burning off residual gas. I will in the following days, replace spark plug 6 as a precaution and to get the experience out of the way. i will also be changing my engine oil as it reeks of gas.

Is it safe to test drive the car around the block a few times? or would you change the oil first? i don't want to put everything together, change the oil, sparks plugs and have another issue crop up. But I guess at that point I'll be taking it to someone more experienced anyway.

"If you have a catted DP, it may be toast now."

Yes I have a catted DP Do you think this is the case if I only drove about 10mins total with the cylinder misfiring? (well specifically, the injector stuck open?) If so how can I test that the Cat is fine?

[oooseun]

Also, i have never had my engine cover off but is this how it's supposed to sound at idle? i couldn't pinpoint it to a source. I also don't have everything bolted down.

[pikcachu]

Originally Posted by oooseun

Also, i have never had my engine cover off but is this how it's supposed to sound at idle? i couldn't pinpoint it to a source. I also don't have everything bolted down.

Yes it sounds like that without the cover...

but Holy smokes

[oooseun]

Originally Posted by pikcachu

Yes it sounds like that without the cover...

but Holy smokes

LOL, thanks!

[XutvJet]

What's the smoke smell like? If it isn't sooty and fuel smelling, it could point to coolant and a head gasket failure.

What are the mods to this car?

[oooseun]

Originally Posted by XutvJet

What's the smoke smell like? If it isn't sooty and fuel smelling, it could point to coolant and a head gasket failure.

What are the mods to this car?

Smoke smells like Gas. I think I'll have the engine run for a few more mins after I change the spark plugs, the volume of the smoke already went down so I think it'll clear up eventually. it's only 50k miles so a gasket failure sounds like a reach(well so did injectors but here we are).

[oooseun]

Ladies and Gentlemen! it's back! but on another cylinder ��

Alright, so i though the issue was gone (and it is technically, no more misfiring on cyl 6, no more clouds of white 91 Oct smoke). So the final step was to do an oil change. I drove the car for about 12mins to warm it up and on the way back in i got a check engine light.

Below is a bootmod3 log. you can see Cyl 4 is now misfiring, the DME codes agree with me. This might just be the car catching up to/with effects of the actual failure, or this is more serious than first thought. The only action i did on Cyl 4 was take out the coil packs to get to the fuel rail. other than that, coils, injectors, spark plugs are all where i left them.

What are your thoughts?

https://www.bootmod3.net/log?id=5f62...729b26771bfa4f

[oooseun]

(hopefully final?) update.

i replaced plug 4 with plug ex-6.
i initially was able to still create misfires (live logging this as I drive on bootmod3) but I later realized that's only when I do something you hardly do in real life and can confuse the engine. Revving in quick succession. i realized I can create misfires in all 6 cyls by tapping the revs successively and quickly. other than that, no more misfires, will keep logging to see if it all holds up!

Thanks everyone.