Car misfire no CEL help!!

nagooyin · 06-09-2021, 10:52 PM

My car started to stutter while at highway cruising speeds and would stutter/shake while trying to accelerate. I limped the car home and it would shake while at idle with no CEL and still couldn't find hidden codes with my OBD2 scanner.

This happened to me a few months prior and the culprit was 1 bad fuel injector that has been replaced out of the 6. The only difference this time is that while at idle there is no sign of white smoke coming out but during the first time it happened there were puffs of white smoke coming out which is a sign of a bad fuel injector.

Do you guys think this is a sign of all faulty fuel injectors? And if it is, would I need to do any sort of coding?

The car is a FBO custom tuned 435i with 109k miles coil packs have 3k miles and brand new NGK spark plugs gapped to .022.

thejeremyman9 · 06-10-2021, 01:49 PM

Tuned with what software? You probably need to uninstall the tune, especially if its BM3 based, as it may be suppressing CELs.

njdangelo · 06-11-2021, 09:07 AM

It would be very rare for an injector to go and there not be a CEL light. Stuttering and shaking while trying to accelerate could also be a boost leak issue which could definitely happen without throwing a code. I see you have a 435... have you checked you charge pipe for cracks? Also how recent was your spark plug install... Might have a loose plug or pack

nagooyin · 06-11-2021, 03:06 PM

Quote:

Originally Posted by njdangelo

It would be very rare for an injector to go and there not be a CEL light. Stuttering and shaking while trying to accelerate could also be a boost leak issue which could definitely happen without throwing a code. I see you have a 435... have you checked you charge pipe for cracks? Also how recent was your spark plug install... Might have a loose plug or pack

i am certain it isn't a boost leak. like i mentioned above, the first time it happened my injector failed and no CEL. i am also full bolt ons meaning upgraded diverter valve and charge pipe included so it can't be a boost leak.

nagooyin · 06-11-2021, 03:10 PM

Quote:

Originally Posted by thejeremyman9

Tuned with what software? You probably need to uninstall the tune, especially if its BM3 based, as it may be suppressing CELs.

yes it is tuned on BM3. should i just flash back to stock and run the car til it flashes CEL? or will that not work.

BMWILUVU · 06-11-2021, 03:19 PM

Quote:

Originally Posted by nagooyin

yes it is tuned on BM3. should i just flash back to stock and run the car til it flashes CEL? or will that not work.

Did you check if the injector from a few months ago sooted up your oxygen sensor? Whats the story with the previous injector replacement, were all injectors replaced and by whom? No coding is needed after an injector replacement, just reset adaptations. I would flash back to stock.

LA1Z24 · 06-11-2021, 04:58 PM

Quote:

Originally Posted by nagooyin

yes it is tuned on BM3. should i just flash back to stock and run the car til it flashes CEL? or will that not work.

Yes do this. There are multiple reports of BM3 suppressing a lot of codes, even misfire codes.

nagooyin · 06-11-2021, 05:07 PM

Quote:

Originally Posted by BMWILUVU

Quote:

Originally Posted by nagooyin

yes it is tuned on BM3. should i just flash back to stock and run the car til it flashes CEL? or will that not work.

Did you check if the injector from a few months ago sooted up your oxygen sensor? Whats the story with the previous injector replacement, were all injectors replaced and by whom? No coding is needed after an injector replacement, just reset adaptations. I would flash back to stock.

i had a shop replace the single injector. it was a used injector i believe roughly 45k miles and im not too sure about O2 sensors.

BMWILUVU · 06-11-2021, 05:21 PM

Quote:

Originally Posted by nagooyin

i had a shop replace the single injector. it was a used injector i believe roughly 45k miles and im not too sure about O2 sensors.

You put in a used injector? I guess I don't blame you each being $300 new. I don't know it could be many things. Your failed injector could have affected the plug or coil or fouled the O2 sensor or even the cat. Then theres the question whether the right injector was replaced and how they determined. A stealership may advise replacing all the injectors for certain legit reasons.

nagooyin · 06-11-2021, 05:24 PM

Quote:

Originally Posted by BMWILUVU

Quote:

Originally Posted by nagooyin

i had a shop replace the single injector. it was a used injector i believe roughly 45k miles and im not too sure about O2 sensors.

You put in a used injector? I guess I don't blame you each being $300 new. I don't know it could be many things. Your failed injector could have affected the plug or coil or fouled the O2 sensor or even the cat. Then theres the question whether the right injector was replaced and how they determined. A stealership may advise replacing all the injectors for certain legit reasons.

i heard that bosch sells all 6 injectors for around 400-500 if im not mistaken. if i get new injectors would i be able to DIY this job at home? havent seen too many fuel injector replacement videos.

thejeremyman9 · 06-11-2021, 05:26 PM

As I said before, flash back to stock and drive the car then scan for codes. For most people new codes pop up immediately after going back to stock and typically point to one cylinder as the problem.

BMWILUVU · 06-11-2021, 05:30 PM

Yes before throwing money at it left and right, you need to know the problem you are dealing with. Get codes scanned. Opt for the most expensive option last not first.

nagooyin · 06-11-2021, 08:25 PM

thanks for ur help guys. i flashed it back to stock and a code popped up right away which was cylinder 2 misfire. next thing i did was swap coil #2 with #4 deleted codes and turned the car on. the misfire switched to cylinder #4 which was such a relief. i got a new coil pack, swapped it and it runs like new. thanks again for everyone who chimed in!

thejeremyman9 · 06-12-2021, 12:02 AM

Quote:

Originally Posted by nagooyin

thanks for ur help guys. i flashed it back to stock and a code popped up right away which was cylinder 2 misfire. next thing i did was swap coil #2 with #4 deleted codes and turned the car on. the misfire switched to cylinder #4 which was such a relief. i got a new coil pack, swapped it and it runs like new. thanks again for everyone who chimed in!

Please post in the BM3 thread in N55 section. This is like the 3rd time in the last few weeks that someone had the exact same thing happen, yet PTF and others continue to argue that BM3 does not suppress CELs/codes.

njdangelo · 06-12-2021, 05:17 AM

Quote:

Originally Posted by nagooyin

Quote:

Originally Posted by njdangelo

It would be very rare for an injector to go and there not be a CEL light. Stuttering and shaking while trying to accelerate could also be a boost leak issue which could definitely happen without throwing a code. I see you have a 435... have you checked you charge pipe for cracks? Also how recent was your spark plug install... Might have a loose plug or pack

i am certain it isn't a boost leak. like i mentioned above, the first time it happened my injector failed and no CEL. i am also full bolt ons meaning upgraded diverter valve and charge pipe included so it can't be a boost leak.

Right but you said this had different symptoms because a failed injector produces smoke and this time it did not. Like I mentioned above I'd check your coil packs/spark plugs

EDIT: just read through the whole chain, looks like it was a pack. Glad you got it sorted

MHF30 · 06-15-2021, 08:25 PM

Quote:

Originally Posted by LA1Z24

Quote:

Originally Posted by nagooyin

yes it is tuned on BM3. should i just flash back to stock and run the car til it flashes CEL? or will that not work.

Yes do this. There are multiple reports of BM3 suppressing a lot of codes, even misfire codes.

Care to share where you've seen this? First time I'm hearing of this.

thejeremyman9 · 06-16-2021, 12:21 AM

Quote:

Originally Posted by MHF30

Care to share where you've seen this? First time I'm hearing of this.

There's 3 threads recently in this general section where the exact same thing as OP as happened. You can also find multiple reports in the BM3 thread in the N55 technical forum, but they get buried quickly due to the number of posts there.

Here's another recent example from this section: https://f30.bimmerpost.com/forums/sh....php?t=1830137

06-09-2021, 10:52 PM	#1
nagooyin Private 3 Rep 50 Posts Drives: bmw 435xi Join Date: Nov 2020 Location: chicago iTrader: (0)	Car misfire no CEL help!! My car started to stutter while at highway cruising speeds and would stutter/shake while trying to accelerate. I limped the car home and it would shake while at idle with no CEL and still couldn't find hidden codes with my OBD2 scanner. This happened to me a few months prior and the culprit was 1 bad fuel injector that has been replaced out of the 6. The only difference this time is that while at idle there is no sign of white smoke coming out but during the first time it happened there were puffs of white smoke coming out which is a sign of a bad fuel injector. Do you guys think this is a sign of all faulty fuel injectors? And if it is, would I need to do any sort of coding? The car is a FBO custom tuned 435i with 109k miles coil packs have 3k miles and brand new NGK spark plugs gapped to .022. __________________ khan nguyen
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06-11-2021, 09:07 AM	#3
njdangelo Captain 436 Rep 844 Posts Drives: 2019 x5 50i Join Date: Sep 2019 Location: CT iTrader: (1)	It would be very rare for an injector to go and there not be a CEL light. Stuttering and shaking while trying to accelerate could also be a boost leak issue which could definitely happen without throwing a code. I see you have a 435... have you checked you charge pipe for cracks? Also how recent was your spark plug install... Might have a loose plug or pack __________________ 2019 x5 50i - current 2016 340i THP stage 2 - gone but not forgotten.
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06-11-2021, 05:26 PM	#11
thejeremyman9 Major General 4358 Rep 7,598 Posts Drives: 2015 BMW 335i Join Date: May 2019 Location: Cali iTrader: (0)	As I said before, flash back to stock and drive the car then scan for codes. For most people new codes pop up immediately after going back to stock and typically point to one cylinder as the problem.
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06-11-2021, 05:30 PM	#12
BMWILUVU Lieutenant Colonel 809 Rep 1,597 Posts Drives: 340ix Join Date: Mar 2017 Location: The Boibs iTrader: (0)	Yes before throwing money at it left and right, you need to know the problem you are dealing with. Get codes scanned. Opt for the most expensive option last not first.
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06-11-2021, 08:25 PM	#13
nagooyin Private 3 Rep 50 Posts Drives: bmw 435xi Join Date: Nov 2020 Location: chicago iTrader: (0)	thanks for ur help guys. i flashed it back to stock and a code popped up right away which was cylinder 2 misfire. next thing i did was swap coil #2 with #4 deleted codes and turned the car on. the misfire switched to cylinder #4 which was such a relief. i got a new coil pack, swapped it and it runs like new. thanks again for everyone who chimed in! __________________ khan nguyen
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06-10-2021, 01:49 PM	#2
thejeremyman9 Major General 4358 Rep 7,598 Posts Drives: 2015 BMW 335i Join Date: May 2019 Location: Cali iTrader: (0)	Tuned with what software? You probably need to uninstall the tune, especially if its BM3 based, as it may be suppressing CELs.
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