Sudden hiccups/studdering

Kevin39 · 06-12-2018, 05:58 PM

E90 N55 70k miles

I have MHD installed but no map or custom tune flashed. Driving down the road at constant speed and it just started hiccuping or missing every 10 seconds or so. It does it immediately if you put a load on it.

I did just fill up with 93 octane about 10min prior so i thought maybe bad gas but I do have an ethanol sensor and it says E11. I would assume if there was a bunch of water in the gas that it would read higher.

The plugs are maybe 1k miles old. I could probably open the gap up a little since I'm not running a tune or ethanol at the moment but it wasn't a problem previously so I don't think that's the cause.

My last guess was maybe it's time for coils? I wouldn't be surprised if they were original. I have the service records from ~35kmiles up to now and they don't appear to have ever been changed. Same with the HPFP.

I took a quick log around the neighborhood hoping someone smarter than me would see something that stands out and maybe point me in a direction to start. Thanks guys.

https://datazap.me/u/kevinc39/misfir...?log=0&data=11

Kevin39 · 06-16-2018, 08:06 AM

No codes other than Cat codes from the downpipe. Nothing popped up in the dash either. I've driven it twice since then and had no issues So who knows. Was going to just buy some coils to have on hand if it acts up again.

lwgrenier · 06-18-2018, 08:36 AM

Quote:

Originally Posted by Kevin39

E90 N55 70k miles

I have MHD installed but no map or custom tune flashed. Driving down the road at constant speed and it just started hiccuping or missing every 10 seconds or so. It does it immediately if you put a load on it.

I did just fill up with 93 octane about 10min prior so i thought maybe bad gas but I do have an ethanol sensor and it says E11. I would assume if there was a bunch of water in the gas that it would read higher.

The plugs are maybe 1k miles old. I could probably open the gap up a little since I'm not running a tune or ethanol at the moment but it wasn't a problem previously so I don't think that's the cause.

My last guess was maybe it's time for coils? I wouldn't be surprised if they were original. I have the service records from ~35kmiles up to now and they don't appear to have ever been changed. Same with the HPFP.

I took a quick log around the neighborhood hoping someone smarter than me would see something that stands out and maybe point me in a direction to start. Thanks guys.

https://datazap.me/u/kevinc39/misfir...?log=0&data=11

Your rail pressure is all over the place. Saw it get as low as 55psi which does not seem right. Could be your hpfp?

Kevin39 · 06-19-2018, 02:43 PM

It's original as far as I know so that could be it. Coils and HPFP were my first guesses as well.

lwgrenier · 06-19-2018, 02:48 PM

I'm at 63k miles and just replaced mine. Was having having intermittent episodes of pretty sever misfiring and showing low fuel pressure. Put a new one in and it solved misfires as well as longish crank and hidden fuel pressure code.

Kevin39 · 06-19-2018, 04:17 PM

Awesome. Sounds like that's probably what it is.

Where is everyone buying pumps and coils these days? I also saw there were both Bosch and Delphi (I think) coils on rock auto or fcp euro. Any reason to go with one over the other?

lwgrenier · 06-20-2018, 07:12 AM

I can't speak to the best place to get coils but I got my pump from getbmwparts. I went with a slightly older model because it was less than half the price of the most recent one and seemed to perform the same. I figure if I can get another 60k miles out of it I'll be happy. Here's the link:

https://www.getbmwparts.com/oem-part...00-13517616446

Also you can return your used pump to them for around $50 back.

vespa · 06-20-2018, 02:39 PM

Yeah, your pump is gone. No signs of coil trouble but if you want to replace them try to find a place that sells genuine Bosch/Delphi parts. Rock Auto coils are Chinese counterfeit junk.

Kevin39 · 06-20-2018, 06:59 PM

Quote:

Originally Posted by vespa

Rock Auto coils are Chinese counterfeit junk.

Thanks for the heads up

06-12-2018, 05:58 PM	#1
Kevin39 Lieutenant 164 Rep 411 Posts Drives: 2011 E90 N55 Join Date: Feb 2016 Location: Indiana iTrader: (0)	Sudden hiccups/studdering E90 N55 70k miles I have MHD installed but no map or custom tune flashed. Driving down the road at constant speed and it just started hiccuping or missing every 10 seconds or so. It does it immediately if you put a load on it. I did just fill up with 93 octane about 10min prior so i thought maybe bad gas but I do have an ethanol sensor and it says E11. I would assume if there was a bunch of water in the gas that it would read higher. The plugs are maybe 1k miles old. I could probably open the gap up a little since I'm not running a tune or ethanol at the moment but it wasn't a problem previously so I don't think that's the cause. My last guess was maybe it's time for coils? I wouldn't be surprised if they were original. I have the service records from ~35kmiles up to now and they don't appear to have ever been changed. Same with the HPFP. I took a quick log around the neighborhood hoping someone smarter than me would see something that stands out and maybe point me in a direction to start. Thanks guys. https://datazap.me/u/kevinc39/misfir...?log=0&data=11 __________________ E90 N55 RWD 6MT MHD Speedtech EFR7670 MFactory LSD
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06-16-2018, 08:06 AM	#2
Kevin39 Lieutenant 164 Rep 411 Posts Drives: 2011 E90 N55 Join Date: Feb 2016 Location: Indiana iTrader: (0)	No codes other than Cat codes from the downpipe. Nothing popped up in the dash either. I've driven it twice since then and had no issues So who knows. Was going to just buy some coils to have on hand if it acts up again.
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06-19-2018, 02:43 PM	#4
Kevin39 Lieutenant 164 Rep 411 Posts Drives: 2011 E90 N55 Join Date: Feb 2016 Location: Indiana iTrader: (0)	It's original as far as I know so that could be it. Coils and HPFP were my first guesses as well.
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06-19-2018, 02:48 PM	#5
lwgrenier First Lieutenant 117 Rep 255 Posts Drives: 2011 e92 335i XDrive Join Date: Oct 2017 Location: New Hampshire iTrader: (0)	I'm at 63k miles and just replaced mine. Was having having intermittent episodes of pretty sever misfiring and showing low fuel pressure. Put a new one in and it solved misfires as well as longish crank and hidden fuel pressure code.
	Appreciate 1 Kevin39164.00 Quote

06-19-2018, 04:17 PM	#6
Kevin39 Lieutenant 164 Rep 411 Posts Drives: 2011 E90 N55 Join Date: Feb 2016 Location: Indiana iTrader: (0)	Awesome. Sounds like that's probably what it is. Where is everyone buying pumps and coils these days? I also saw there were both Bosch and Delphi (I think) coils on rock auto or fcp euro. Any reason to go with one over the other?
	Appreciate 0 Quote

06-20-2018, 07:12 AM	#7
lwgrenier First Lieutenant 117 Rep 255 Posts Drives: 2011 e92 335i XDrive Join Date: Oct 2017 Location: New Hampshire iTrader: (0)	I can't speak to the best place to get coils but I got my pump from getbmwparts. I went with a slightly older model because it was less than half the price of the most recent one and seemed to perform the same. I figure if I can get another 60k miles out of it I'll be happy. Here's the link: https://www.getbmwparts.com/oem-part...00-13517616446 Also you can return your used pump to them for around $50 back.
	Appreciate 1 Kevin39164.00 Quote

06-20-2018, 02:39 PM	#8
vespa First Lieutenant 217 Rep 245 Posts Drives: 2011 335i Join Date: Dec 2014 Location: Thousand Oaks iTrader: (0)	Yeah, your pump is gone. No signs of coil trouble but if you want to replace them try to find a place that sells genuine Bosch/Delphi parts. Rock Auto coils are Chinese counterfeit junk.
	Appreciate 0 Quote