[Milan]

My next vote is injectors...they will cause similar symptoms to what you are describing

[eforty6_m3]

Originally Posted by 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.

I know, I know...talk about dropping the ball. My weekends just get so booked up with family obligations. I might have to try and book myself as busy to devote my Sunday morning to doing this. Thanks for the kick in the ass!

Originally Posted by Milan

My next vote is injectors...they will cause similar symptoms to what you are describing

Probably...stay tuned!

[eforty6_m3]

Originally Posted by 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.

So I tried your original suggestion yet again (flooring in a low gear to strain the fuel system), and even after a few repeated attempts, I could not get any codes to trigger. The car stumbled, as expected, but threw no CEL nor any codes, even after holding the gas down for more than enough time. The car has been totally fine since I first reported the issue, which is good, but strange.

I'm starting to wonder if it was just some sort of fluky anomaly, since it hasn't reared it's ugly head since.

[eforty6_m3]

I know GreaseMonkey is going to give me shit, but the holidays with a 1 year old and family who wants nothing more than to see him, it's tough to find the free time to swap coils.

That said, I did get my battery replaced from BMW on Tuesday morning. My car then sat until Friday morning (I'm noticing a pattern here where these rough starts are happening after the car has sat for 2 or 3 days) and it had a really rough start. So bad, I actually had to turn the car off and start it back up 3 times total. No half engine/limp mode icon ever turned up, but the CEL is on and I did find these fault codes:



Little different than the first batch of codes I had received. And it appears as though both banks are now affected.

[GreaseMonkey]

I have no intention of giving you any crap, not to worry! Believe me, I understand exactly how little time there is in the day. Just hope you get everything figured soon, that'll be a huge relief.

Hope you had a great holiday and happy new year!

[eforty6_m3]

Originally Posted by GreaseMonkey

I have no intention of giving you any crap, not to worry! Believe me, I understand exactly how little time there is in the day. Just hope you get everything figured soon, that'll be a huge relief.

Hope you had a great holiday and happy new year!

Well that's great to hear. Ha! Thanks for the kind words and for all the help. I'll let you know once in manage to find the time to address this. Might require a "sick" day from work.

Happy New Year to you, as well. Cheers!

[TDI_G]

Sounds to me like it is a fuel system issue. I had a couple injectors that would leak when the car sat over night. Also had HPFP issues. I installed a new HPFP (really not that difficult to change) and installed a couple injectors that I knew were giving me issues (wet spark plugs after sitting a couple hours) and the car is running great now. I also replaced coils and plugs while I was at it to rule them out. None of it is extremely expensive if you can do the work yourself.

[eforty6_m3]

Originally Posted by TDI_G

Sounds to me like it is a fuel system issue. I had a couple injectors that would leak when the car sat over night. Also had HPFP issues. I installed a new HPFP (really not that difficult to change) and installed a couple injectors that I knew were giving me issues (wet spark plugs after sitting a couple hours) and the car is running great now. I also replaced coils and plugs while I was at it to rule them out. None of it is extremely expensive if you can do the work yourself.

Thanks for the feedback, it's really appreciated!

Here is the latest:





Evidently, the HPFP is fine (I'd hope so, seeing as the car is already on it's 3rd one and you'd hope that BMW has got their shit together with these by now). But the fault with the low pressure fuel pump has occurred 34 times now, so something clearly is not right there.

BMW of Warwick quoted me $470.99 (before my BMWCCA discount) for the repair kit, so I'll most likely be buying this elsewhere, as I've seen better prices from the likes of FCPEuro and Autohaus.

I need to do some research and figure out if this is a repair that I can do myself, or if I'm better off leaving this to the pro's. For the entire job, BMW quoted me (I don't have the exact figure) somewhere in the neighborhood of $875, and I absolutely don't feel like paying that. Worst case, I'll see what some of the local indy shops would charge for this job.

Now, the BMW writeup does indicate that there were misfires with cylinders 1 & 6 (which isn't a total surprise, per the fault codes I've received), but there's no sure way to tell if replacing the pump will address the misfires, as well. I'm thinking this may require replacing of all injectors and plugs, but I'd like to inspect the plugs after letting the car sit for a few days to see if they're soaked with gasoline or not. That would tell me whether or not the injector is leaking. I can at least do that before getting the LPFP replaced.

Monday is a holiday, so that may end up being my diagnosis day. I also need to check out something I've noticed after short highway drives, where steam is emitting from my passenger side grill after I've parked. I'm thinking it's a small leak somewhere in the cooling system, but nothing is obviously evident so this may require some up close and dirty detective work.

Thanks again to everyone who's chimed in up to this point.

While you're at it, also set aside some time to rotate your drivers side muffler counterclockwise a bit...the pic in your sig is making my ocd kick into overdrive lol

[eforty6_m3]

Originally Posted by FCobra94

While you're at it, also set aside some time to rotate your drivers side muffler counterclockwise a bit...the pic in your sig is making my ocd kick into overdrive lol

I guess that's what I get for going with a Megan exhaust. Doesn't fit 100% perfectly, but it's damn near close. I'll see what I can do once the weather warms up..just for you, dude!

[TDI_G]

I would try replacing the low pressure fuel sensor before changing the LPFP itself. Seems to be a common failure item from what I have gathered. I went ahead and replaced mine when I changed the HPFP since I was already in there. The dealer I picked it up from told me that they replace them all the time. I needed mine right away so I purchased it from the dealer rather than saving some money and purchasing from an online vendor. Just something to think about.

[wren57]

Replace your plugs and while you're at it check for VCG leaks.

Also now is a good time to upgrade LPFP.

[TDI_G]

This is the part number 13537614317

[jwebb335xi]

Originally Posted by sed335i

I know GreaseMonkey is going to give me shit, but the holidays with a 1 year old and family who wants nothing more than to see him, it's tough to find the free time to swap coils.

That said, I did get my battery replaced from BMW on Tuesday morning. My car then sat until Friday morning (I'm noticing a pattern here where these rough starts are happening after the car has sat for 2 or 3 days) and it had a really rough start. So bad, I actually had to turn the car off and start it back up 3 times total. No half engine/limp mode icon ever turned up, but the CEL is on and I did find these fault codes:



Little different than the first batch of codes I had received. And it appears as though both banks are now affected.

Leaky Injectors??? Do you smell fuel?

[eforty6_m3]

Originally Posted by TDI_G

I would try replacing the low pressure fuel sensor before changing the LPFP itself. Seems to be a common failure item from what I have gathered. I went ahead and replaced mine when I changed the HPFP since I was already in there. The dealer I picked it up from told me that they replace them all the time. I needed mine right away so I purchased it from the dealer rather than saving some money and purchasing from an online vendor. Just something to think about.

I might do this while I do the pump, just to be safe. My main reason for thinking it's not the sensor is how the ECU has 34 occurrences of the LPFP fault. So that would explain the issues I've been having with the rough starts. Besides, from what I've seen, a faulty sensor seems to throw other codes that I have yet to pull.

Originally Posted by wren57

Replace your plugs and while you're at it check for VCG leaks.

Also now is a good time to upgrade LPFP.

I think I want to confirm whether or not my injectors are leaking before I replace the plugs, but that is definitely on my To Do list for the near future. She was about due, anyway.

As for the VCG, it's definitely leaking. This was discovered during a BMWCCA Undercarriage Event that I attended recently. I'm thinking this will be a spring project, however, as it's just too damn cold to spend the entire day in my non-heated, New England garage. And the leak doesn't appear to be all that bad.

I think I'll stick with the standard LPFP, as there's a decent chance I may try and sell this car in a few years. So I don't need to do anything too crazy for now.

Originally Posted by TDI_G

This is the part number 13537614317

Thanks, man!!

Originally Posted by jwebb335xi

Leaky Injectors??? Do you smell fuel?

I assume you mean do I smell fuel after the car has sat for a few days and I try to start it? No, not really. But would I smell fuel from inside the car when trying to start it if they were leaking? Or should I leave the hood open and immediately get out of the car and smell for gas when starting the car?

[TDI_G]

You can pull spark plugs after the car has sat overnight or even a few hours and any plugs that are wet with fuel have leaking injectors.

[Jeff@TopGearSolutions]

Typically, when your fuel injectors leak overnight you can smell fuel in the morning during start up. (But not always).

But you could also just pull the spark plugs and see if they smell and/or fouled with fuel.

[eforty6_m3]

Originally Posted by TDI_G

You can pull spark plugs after the car has sat overnight or even a few hours and any plugs that are wet with fuel have leaking injectors.

Originally Posted by Jeff@TopGearSolutions

Typically, when your fuel injectors leak overnight you can smell fuel in the morning during start up. (But not always).

But you could also just pull the spark plugs and see if they smell and/or fouled with fuel.

Yeah, that's my plan. I work from home tomorrow, so I won't need to use my car from the time I get home today around 5pm until I have to leave to pickup my son from daycare tomorrow around 4pm. So I'll probably check the plugs sometime tomorrow morning, as it will have been sitting for at least 15 or so hours.

If I do find that an injector(s) is leaking, is it acceptable to replace just the culprits? Or do they need to all be replaced? Or just the bank? etc etc.

[TDI_G]

Keep in mind that you cannot mix series 10 and higher (or is it 11 and higher?) injectors with earlier injectors. You will need INPA to code the injectors when you swap them.

[eforty6_m3]

Originally Posted by TDI_G

So the route I went, and I am not necessarily recommending this route and will likely be flamed for doing this, was I ordered remanufactured (aka cleaned and tested) injectors and only swapped the bad ones and it worked like a charm. This can be hit and miss and you do that at your own risk if you go that route. You cannot mix series 10 and higher (or is it 11 and higher?) injectors with earlier injectors. I will likely replace all 6 injectors with new series 12 injectors in the near future but I went this route first in when chasing down my misfire issues. You will need INPA to code the injectors when you swap them.

Fair enough. I'm not convinced it is my injectors, though, so I'll have to continue to play it by ear until I can confirm it, one way or the other.

I definitely don't have INPA and not sure I want to invest in any of the necessary software and cables, especially if I decide to part with the car in the next year or so.

Thanks for the input!

[eforty6_m3]

The Latest:

I swapped out the LPFP yesterday morning. Ended up being a fairly straight-forward job. I noticed right off the bat that the car seems to be starting up a bit quicker than it had before. Not that it was long-cranking prior to that, but it seems to now start up immediately, as opposed to cranking for a second or two.

I cleared all the existing fault codes and will now monitor the car to see if the new fuel pump addresses my issue or not. I'm fairly certain it needed to be replaced, regardless, so hopefully no other issues are still present. If so, I'll deal with them as they arise.

As for the LPFP, I bought it from FCP Euro, for a few reasons. 1) It was on sale for only $173.99 and 2) LIFETIME WARRANTY.

I got to put my new garage cart to use for this job:



I did the job alone, so I didn't exactly have a free set of hands to take photos during the process. But here is the old pump:

[eforty6_m3]

Another week has gone by and yet another rough start. Granted, this was the first rough start I've experienced since swapping out the LPFP. At this point, I'm starting to suspect the injectors. So I'll have to do some more detective work and see if one (or more) injector is leaking.

Yay...