[eforty6_m3]

....NOT

This morning, I started my car after not driving it since Friday night. It started up, but very roughly, and with fluctuating RPM's. After some sputtering, the CEL came on. I gave it a few seconds to see if the RPM's would even out, but they didn't, so I shut the car off. I waited another 4-5 seconds and restarted. It wasn't shaking anywhere near as bad, so I gave the gas a few revs and backed the car out of the garage. I checked for smoke or any odd smells, but noticed nothing. The CEL did not come back on and the RPM's eventually evened out and the car drove completely fine, so off to work I went.

Upon arriving to work, I took a few minutes to check for codes and this is what I found:



I tried clearing the codes while the car was still running, which I don't believe will work when using the Torque app. I'll try to clear them before starting the car on my way home and see if anything triggers during my drive.

Also, before anyone rips me a new one for not "searching first", I did search. And most of the threads I found were a page, maybe 2, with no actual conclusions reached. It would be helpful if those folks who started related threads actually updated said threads with outcomes. What ended up being the issue? What needed to be fixed? Etc. etc.

That said, based on the codes above, what should I look at first? I've seen that the 02 sensors could be a culprit, seeing how the entire bank was affected. Am I on the right path? I was thinking of doing my plugs soon, anyway, so should I do that to rule anything out or will plugs not really tell me anything with the triggered codes?

Thanks in advance.

[Jeff@TopGearSolutions]

P3090 I believe is high pressure fuel pump. That is likely the issue.

Is the vehicle stock? How many miles on the spark plugs?

[eforty6_m3]

Originally Posted by Jeff@TopGearSolutions

P3090 I believe is high pressure fuel pump. That is likely the issue.

Is the vehicle stock? How many miles on the spark plugs?

Seriously?! UGHH. It's already on it's 3rd HPFP, which all happened with the previous owner (last replaced at 43,341 miles....she's currently sitting on 93,313 miles).

And the plugs were last done by me at 60,500 miles, so roughly 32,813 miles ago.

It's bone stock aside from the BMS DCI and a catback exhaust.

I know that a long crank is another sign of a failing HPFP, but I definitely did not experience that this morning. If that counts for anything.

[eforty6_m3]

Minor update: No codes throw on the drive home yesterday (roughly 10 mile drive, 90% highway).

About to drop my son off at daycare, so we'll see how she does on a true cold start.

[GreaseMonkey]

Try to floor it in a high gear at low speed, this will strain the fuel system and force any weakness to show up. If it's the HPFP the car will stutter/jerk, throw a code and go into limp mode most likely. Check for codes, then shut the car off and turn it back on, you should be good to go after restarting. If it's the HPFP take an easy drive home or directly to your repair shop.

Just a note: do this on an empty road with room to pull over in case you lose power, safety first when trying to disable your vehicle on purpose.

[eforty6_m3]

Other than a weak battery from my dumb ass forgetting to remove the OBDII bluetooth dongle, she started up just fine. Checked for codes after getting back home and still nothing.

Does the app you're using allow you to log? Or see fuel pressure values, etc.?

It's tough to tell which parts are bad if you have no idea how they're behaving.

[eforty6_m3]

Originally Posted by GreaseMonkey

Try to floor it in a high gear at low speed, this will strain the fuel system and force any weakness to show up. If it's the HPFP the car will stutter/jerk, throw a code and go into limp mode most likely. Check for codes, then shut the car off and turn it back on, you should be good to go after restarting. If it's the HPFP take an easy drive home or directly to your repair shop.

Just a note: do this on an empty road with room to pull over in case you lose power, safety first when trying to disable your vehicle on purpose.

Really?! OK, I might just try this later on today on a back road somewhere. I'll be in touch.

Originally Posted by FCobra94

Does the app you're using allow you to log? Or see fuel pressure values, etc.?

It's tough to tell which parts are bad if you have no idea how they're behaving.

Good question. I'm pretty sure Torque (the app I use) does allow for logging, so I'll try and do that when I leave to go pick up my son from daycare. I'll update with any results. Thanks for the suggestion!

[eforty6_m3]

Originally Posted by GreaseMonkey

Try to floor it in a high gear at low speed, this will strain the fuel system and force any weakness to show up. If it's the HPFP the car will stutter/jerk, throw a code and go into limp mode most likely. Check for codes, then shut the car off and turn it back on, you should be good to go after restarting. If it's the HPFP take an easy drive home or directly to your repair shop.

Just a note: do this on an empty road with room to pull over in case you lose power, safety first when trying to disable your vehicle on purpose.

Tried this yesterday and all the car really did was hesitate/stutter for a split second whenever I would floor it in a high gear @ a low speed. No codes, no CEL, no limp mode.

[eforty6_m3]

Originally Posted by FCobra94

Does the app you're using allow you to log? Or see fuel pressure values, etc.?

It's tough to tell which parts are bad if you have no idea how they're behaving.

Apparently it's super easy and I'm just an idiot. So I'll try this after work today and report back with my findings.

[GreaseMonkey]

Originally Posted by sed335i

Tried this yesterday and all the car really did was hesitate/stutter for a split second whenever I would floor it in a high gear @ a low speed. No codes, no CEL, no limp mode.

If it felt like power was cutting out, keep your foot on the gas and let it continue to stumble. It's a very weird feeling to keep the pedal down when the car is reacting badly, but it takes a few seconds of continued stumbling to really overdrive the fuel pump and force the issue.

[eforty6_m3]

Originally Posted by GreaseMonkey

If it felt like power was cutting out, keep your foot on the gas and let it continue to stumble. It's a very weird feeling to keep the pedal down when the car is reacting badly, but it takes a few seconds of continued stumbling to really overdrive the fuel pump and force the issue.

OK...I'll try it again. I was fairly certain that I was keeping the pedal down for a good 3-4 seconds after the initial stumble.

This morning, car started up perfectly fine and drove to work totally normally. One bit of positive news is that I spoke with my SA at the dealer I usually go to for jobs bigger than I can handle and my car is covered under the extended warranty on the HPFP:

https://www.scribd.com/doc/153404704...-Extension-TSB

Only thing is, the warranty covers 10 years or 120k miles, and go figure that my 10 year mark is up on December 31st. So I need to trigger the fault codes/CEL and hope that the issue IS the HPFP in order for it to get replaced with no out of pocket expense prior to 12/31. FML...

[eforty6_m3]

Originally Posted by GreaseMonkey

If it felt like power was cutting out, keep your foot on the gas and let it continue to stumble. It's a very weird feeling to keep the pedal down when the car is reacting badly, but it takes a few seconds of continued stumbling to really overdrive the fuel pump and force the issue.

Tried this again and as much as it hurt to "punish" my car, I was able to trigger another fault code. This time, however, it was only the P0306 code (cylinder 6 misfire detected...pardon the uber blurry image):



Does this potentially mean the issue lies specifically within that one cylinder? Bad plug and/or coil and/or injector? Or could it still potentially be the HPFP?

I haven't had any issues with the car since that one day, aside from the intentional "punishment" detailed above.

Thoughts?

[YoungBlood]

Have ignition coils been replaced? All my misfires I've gotten have been ignition or MOSFET related on this car

[eforty6_m3]

Originally Posted by YoungBlood

Have ignition coils been replaced? All my misfires I've gotten have been ignition or MOSFET related on this car

Not since I've had the car. I've read conflicting reports on coils. As to whether they should be replaced as preventative maintenance or replaced as needed. I hadn't had a reason to replace them until recently.

I assume coils should be replaced as a set, versus individually. Right?!

[klipse]

Good luck getting this fixed! For some reason, I can't view the images.

[GreaseMonkey]

Let the car sit overnight, then swap the #6 coil with one in Bank 1 (1,2, or 3) and take a good look at the #6 plug for any signs of trouble. If the injector is leaking, the plug will be soaked in fuel from the car sitting overnight. Try to recreate the error again, if #6 is still the problem it could be the plug or injector. HPFP would throw more codes than just a single cylinder misfire.

I had all sorts of random issues when I had a leaking injector, but a fuel soaked plug is a clear indicator of leakage.

Good luck!

[eforty6_m3]

Originally Posted by klipse

Good luck getting this fixed! For some reason, I can't view the images.

Thanks, man.

Images should be fixed now. Switched from hosting via Google to Flickr.

Originally Posted by GreaseMonkey

Let the car sit overnight, then swap the #6 coil with one in Bank 1 (1,2, or 3) and take a good look at the #6 plug for any signs of trouble. If the injector is leaking, the plug will be soaked in fuel from the car sitting overnight. Try to recreate the error again, if #6 is still the problem it could be the plug or injector. HPFP would throw more codes than just a single cylinder misfire.

I had all sorts of random issues when I had a leaking injector, but a fuel soaked plug is a clear indicator of leakage.

Good luck!

Good call! Might try this over the weekend, when I have a bit more free time. I'll keep you posted. I appreciate the help!

[eforty6_m3]

Haven't had any time to swap coils, too much going on during the holiday season.

That said, I did encounter another dead battery (side note, the first time I experienced the rough start, CEL, limp mode last month was right after jumping my car due to a dead battery) and sure enough, it had a very rough start, much like it did the last time.

I never got the CEL to come on, however, and the RPMs eventually evened out and the car started to run smooth. No codes, either.

I'm probably grasping at straws here, but could a drained battery have anything to do with the symptoms I'm seeing here? I'm going to assume no, but I guess it can't hurt to ask.

Aside from this latest incident, my car has been running excellent. No other symptoms, no other rough starts or rough running. If it is my HPFP, I only have until 12/31 to prove it before the extended warranty runs out for me. Go figure.

[Milan]

Is your alternator bad? If you have low voltage you will have a ton of weird issues

[eforty6_m3]

Originally Posted by Milan

Is your alternator bad? If you have low voltage you will have a ton of weird issues

Nope, alternator is fine. Had the battery and alternator tested last week and the only issue is the battery. Hoping to get that replaced in the next week or two.

[GreaseMonkey]

Please swap the coil asap, just so you can eliminate possible major issues if the issue switches to the new cylinder. If it doesn't move, you'll have more worrisome issues that need faster attention.

Good luck.