Sputtering/misfire cyl.1 couldn’t be fuel pump?

[Tonynotoes]

I noticed my car was sounding different when I accelerated hard and felt a loss of power from 4-5k rpm for a few weeks, maybe even a month. plugged in a few days ago and it was saying cylinder 1 misfire, with no other info. a couple days later I topped up the coolant a small amount and everything went back to normal, I really think that is a Coincidence but my car was pulling like a train again. I’m stuck, I’ve ordered an MHD scanner, here’s the LPFP log. Please if anyone could help

If anyone has any sort of ideas or has the same problem let me know. Me and my mechanic are struggling because the codes are useless and I don’t want to throw £££ at it if I don’t know what the issue is.

Some info on the car itself

2006 e92 bmw 335i 135k miles

MHD stage 2

Turbos replaced with oem bmw 130k

 

[AzNdevil]

How comes it’s only just running like shit? Will that gradually get worse or stay the same? Do u think custom map would work better in my favour at this point?

good question, honestly your guess is as good as mine.... these cars usually underboost for whatever reason, the only times it overboosts is when upgraded inlets/upgraded turbos/catless downpipes without the proper map

dragging wastegate actuator arms is also an issue but usually on older turbos with enough heat cycles and wear and tear

boost solenoids may also be an issue but again usually they underboost instead of overboost

if you can do the work yourself, checking vacuum/wastegate actuator is free (except for a mittyvac of course)

you arent running a jb4 at the same time i suppose? and you have catless downpipes right? and a stock 2.5bar map sensor

 

[Tonynotoes]

good question, honestly your guess is as good as mine.... these cars usually underboost for whatever reason, the only times it overboosts is when upgraded inlets/upgraded turbos/catless downpipes without the proper map

dragging wastegate actuator arms is also an issue but usually on older turbos with enough heat cycles and wear and tear

boost solenoids may also be an issue but again usually they underboost instead of overboost

if you can do the work yourself, checking vacuum/wastegate actuator is free (except for a mittyvac of course)

you arent running a jb4 at the same time i suppose? and you have catless downpipes right? and a stock 2.5bar map sensor

I replaced the boost solenoids about 6k miles ago?

No jb4 just stage 2 mhd and catless Downpipes, changed the map today seems to be runninn no different to the 98oct map. still idling a lil higher(sometimes) but combustion misfire cyl.1 on a WOT pull

Pulling my hair out with this.

Here’s a screenshot of recent code history(just today)

I keep forgetting to say but everytime I get the code I can clear it while driving and it’s back to normal straight away. Just run like shit until I clear the codes. Ive only just recently started getting the code more in the last couple weeks so I decided to buy the flasher as it would make life easier. But even when I didn’t have the OBD flasher and I got a check engine light it would go away on its own within a couple of minutes on driving.

Once again thanks for ur replies

 

[AzNdevil]

I replaced the boost solenoids about 6k miles ago?

No jb4 just stage 2 mhd and catless Downpipes, changed the map today seems to be runninn no different to the 98oct map. still idling a lil higher(sometimes) but combustion misfire cyl.1 on a WOT pull

Pulling my hair out with this.

Here’s a screenshot of recent code history(just today)

I keep forgetting to say but everytime I get the code I can clear it while driving and it’s back to normal straight away. Just run like shit until I clear the codes. Ive only just recently started getting the code more in the last couple weeks so I decided to buy the flasher as it would make life easier. But even when I didn’t have the OBD flasher and I got a check engine light it would go away on its own within a couple of minutes on driving.

Once again thanks for ur replies

well.... like i said from the previous logs you are having throttle closures from overboost which causes issues in the first place

if it wasnt overboosting i would suggest a new set of plugs and coils....

 

[Tonynotoes]

well.... like i said from the previous logs you are having throttle closures from overboost which causes issues in the first place

if it wasnt overboosting i would suggest a new set of plugs and coils....

I’m going to reset adaptations tomorrow and see if that changes anything..

 

[odesh]

Log-06-14-2024-19-10-32

Uploaded by API.

www.spoolstreet.com

V7 log, no timing corrections. Still misfiring cyl 1 on hard acceleration.

You are running super lean on both banks according to logs. If the car actually ran that lean, the engine would have already grenaded itself. Prob something to do with adaptations or O2 sensors.

This would explain why it's running like shit, since the DME is trying to compensate with dumping more fuel in to the mix. We saw this couple weeks ago when other member was having a similar problem and it was fixed by resetting the O2 adaptations. Here is that conversation.

Hopefully you manage to fix the issue.

 

[Tonynotoes]

You are running super lean on both banks according to logs. If the car actually ran that lean, the engine would have already grenaded itself. Prob something to do with adaptations or O2 sensors.

This would explain why it's running like shit, since the DME is trying to compensate with dumping more fuel in to the mix. We saw this couple weeks ago when other member was having a similar problem and it was fixed by resetting the O2 adaptations. Here is that conversation.

Hopefully you manage to fix the issue.

Thanks so much for your response bro, I’m gonna go outside and reset all adaptations except the battery in next few hours. Let me know if that’s a bad idea and which specific adaptations I need to reset.

The car itself seems to be running smooth like usual unless I’ve got my foot down a bit. From about 2.5k revs to 4.5k it sputters like crazy. Then high rev range it pulls. That’s if it doesn’t misfire and get EML light. It’s annoying because wits only just started happened, had the map for about 5-6 months running smooth then this started happening.

Ive been getting 29CD code regarding combustion misfires. 2C7B oxygen sensor after catalytic converter, I just thought this would be my catless downpipes.

Thanks again, any info really appreciated.

 

[Tonynotoes]

Thanks so much for your response bro, I’m gonna go outside and reset all adaptations except the battery in next few hours.

The car itself runs smooth like usual unless I’ve got my foot down a bit. From about 2.5k revs to 4.5k it sputters like crazy. Then high rev range it pulls. That’s if it doesn’t misfire and get EML light. It’s annoying because wits only just started happened, had the map for about 5-6 months running smooth then this started happening.

Ive been getting 29CD code regarding combustion misfires. 2C7B oxygen sensor after catalytic converter, I just thought this would be my catless downpipes.

Thanks again, any info really appreciated.

lol reset adaptations and my car is idling with loads of codes until I clear them. What should I do? Seems to running better but o2 sensors are deffo fucked ad they spoke everytime I get onto throttle

 

[odesh]

lol reset adaptations and my car is idling with loads of codes until I clear them. What should I do? Seems to running better but o2 sensors are deffo fucked ad they spoke everytime I get onto throttle

Those codes are normal after full adaptation reset. That's why I never really do that to all adaptations, lol. Should go away by driving. Atleast has been like that for me.

If they don't, just reset/calibrate the throttle position and they should go away. This can be done like this:

1. Insert key, foot off the brake, foot off the gas.
2. press start button.
3. Press on gas pedal all the way down for 30 seconds.
4. While foot on pedal at 30 second mark press start button, release gas.
5. Leave key in, wait a full 2 min to start, press brake hit start button and drive.
6. Instant power.

Also if you manage to do a log, send one here. Hopefully we can figure it out.

 

[Tonynotoes]

Those codes are normal after full adaptation reset. That's why I never really do that to all adaptations, lol. Should go away by driving. Atleast has been like that for me.

If they don't, just reset/calibrate the throttle position and they should go away. This can be done like this:

1. Insert key, foot off the brake, foot off the gas.
2. press start button.
3. Press on gas pedal all the way down for 30 seconds.
4. While foot on pedal at 30 second mark press start button, release gas.
5. Leave key in, wait a full 2 min to start, press brake hit start button and drive.
6. Instant power.

Also if you manage to do a log, send one here. Hopefully we can figure it out.

Bro I only just seen this I was panicking, ended up doing the steps you told me earlier form a Google search, pulled up to the garage to put fuel in, turned it back on and it went crazy! Thanks for your help!

I did a pull earlier didn’t really do much misfired soon as wot at 3-4k revs got EML light straight away “combustion misfires cyl1” The car seems to running a lot smoother than it was before after the resets when driving idling normally.

My lambda banks are just crazy in every log I do, lit off the chart, could this be the cause? Once reset was fine for a few miles soon as foot is down the slightest goes from 14-15 to like the max 200 n something.

Log-06-19-2024-16-03-53

Uploaded by API.

www.spoolstreet.com

 

[odesh]

lol reset adaptations and my car is idling with loads of codes until I clear them. What should I do? Seems to running better but o2 sensors are deffo fucked ad they spoke everytime I get onto throttle

Those codes are normal after full adaptation reset. That's why I never really do that to all adaptations, Should go away by driving. Atleast has been like that for me.

If they don't, just reset/calibrate the throttle position and they should go away. This can be done like this:

1. Insert key, foot off the brake, foot off the gas.
2. press start button.
3. Press on gas pedal all the way down for 30 seconds.
4. While foot on pedal at 30 second mark press start button, release gas.
5. Leave key in, wait a full 2 min to start, press brake hit start button and drive.
6. Instant power.

Bro I only just seen this I was panicking, ended up doing the steps you told me earlier form a Google search, pulled up to the garage to put fuel in, turned it back on and it went crazy! Thanks for your help!

I did a pull earlier didn’t really do much misfired soon as wot at 3-4k revs got EML light straight away “combustion misfires cyl1” The car seems to running a lot smoother than it was before after the resets when driving idling normally.

My lambda banks are just crazy in every log I do, lit off the chart, could this be the cause? Once reset was fine for a few miles soon as foot is down the slightest goes from 14-15 to like the max 200 n something.

Log-06-19-2024-16-03-53

Uploaded by API.

www.spoolstreet.com

Yeah I can see that on the log. And yes, that will cause massive jerking and misfires. Been there, done that.

Does the car run smooth before hitting the 4k rpm? Also, what are the AFRs like on the idle?

 

[Tonynotoes]

Those codes are normal after full adaptation reset. That's why I never really do that to all adaptations, Should go away by driving. Atleast has been like that for me.

If they don't, just reset/calibrate the throttle position and they should go away. This can be done like this:

1. Insert key, foot off the brake, foot off the gas.
2. press start button.
3. Press on gas pedal all the way down for 30 seconds.
4. While foot on pedal at 30 second mark press start button, release gas.
5. Leave key in, wait a full 2 min to start, press brake hit start button and drive.
6. Instant power.

Yeah I can see that on the log. And yes, that will cause massive jerking and misfires. Been there, done that.

Does the car run smooth before hitting the 4k rpm? Also, what are the AFRs like on the idle?

I was about to buy stage 2 fuel pump, injectors sparks and coils… LOL. Do u think it’s just the o2 sensors then? Even if it’s running rich etc? I’m clueless with logs and stuff so thanks so much for you quick responses! The cars running smooth up until around about there could even be 3k revs. I think the AFRs are about 14-15 on idle. I was watching the log earlier soon as I step on the throttle it’s 234 or whatever the max is.

The other guy said I’m over boosting is this going to be a cause or an issue as well? As the power delivery is fine but I don’t want to break anything either. Turbos were OEM fitted about 5k miles ago

 

[Tonynotoes]

Just to Add to this just check logs for AFR psi, and seems to stay as it should before boost(low rpm) on the build up to boost. It’s just on deceleration it seems to go to 234.95

 

[odesh]

Just to Add to this just check logs for AFR psi, and seems to stay as it should before boost(low rpm) on the build up to boost. It’s just on deceleration it seems to go to 234.95

Yeah you can only understand logs by trying to study them. It comes with time, so no worries. I try answer every question, let's see.

234 is the maximum lean condition that the sensor can read. When you let of the gas, it's normal to go that high since the injectors are not injecting any fuel at that moment since you are not demanding any power.

14-15 AFR on idle is totally normal. Usually when O2-sensors are out, the AFRs tend to creep up while idling when they get hot. But again, every case is different.

I wouldn't say you are over boosting. Idk where the other person got that idea. The boost target seems to be 15psi on stage 2 map and your logs seem to stay under that limit. The throttle closure happens (most likely) due to the missfire detection or lean condition detection. The engine is just trying to protect itself.

Does the car do that only on full out throttle acceleration or on lighter acceleration too? What I mean, does it do the same when you try to come to acceleration little softer?

If it does, you can try this: Since the turbos were replaced 5k ago, please check that the O2-sensors are plugged the right way, aka not mixed. If they are not mixed, unplug both precat O2-sensors. The connectors can be found on the top of engine, next to the fuel rail. This will put the car on the open loop mode regarding the O2-sensors. This same thing happens when you start the car when it's cold. I guess you can call it static mode. The car will just run rich. You can drive the car without it going to limp mode because you have the MHD flashed. Try driving the car softly and feel how it feels. Lock the gearbox to 2nd or 3rd gear so you have more control over what's happening. If it works on lighter throttle, you can try accelerating harder. Just don't go nuts with it, like WOT full rev range pulls, lol. See if that will let the car rev smooth over 3-4k rpm.

By doing this, we can limit out the O2-sensor faults. Just be careful and don't go nuts.

It's starting to be night where I live. I will check forums right on the morning when I get to work. Good luck.

 

[odesh]

I went out and got you a picture of those. The black wired one should be on the front connector and the grey should be on the back one. My car doesn't have second one since I'm running single turbo.

 

[Tonynotoes]

Yeah you can only understand logs by trying to study them. It comes with time, so no worries. I try answer every question, let's see.

234 is the maximum lean condition that the sensor can read. When you let of the gas, it's normal to go that high since the injectors are not injecting any fuel at that moment since you are not demanding any power.

14-15 AFR on idle is totally normal. Usually when O2-sensors are out, the AFRs tend to creep up while idling when they get hot. But again, every case is different.

I wouldn't say you are over boosting. Idk where the other person got that idea. The boost target seems to be 15psi on stage 2 map and your logs seem to stay under that limit. The throttle closure happens (most likely) due to the missfire detection or lean condition detection. The engine is just trying to protect itself.

Does the car do that only on full out throttle acceleration or on lighter acceleration too? What I mean, does it do the same when you try to come to acceleration little softer?

If it does, you can try this: Since the turbos were replaced 5k ago, please check that the O2-sensors are plugged the right way, aka not mixed. If they are not mixed, unplug both precat O2-sensors. The connectors can be found on the top of engine, next to the fuel rail. This will put the car on the open loop mode regarding the O2-sensors. This same thing happens when you start the car when it's cold. I guess you can call it static mode. The car will just run rich. You can drive the car without it going to limp mode because you have the MHD flashed. Try driving the car softly and feel how it feels. Lock the gearbox to 2nd or 3rd gear so you have more control over what's happening. If it works on lighter throttle, you can try accelerating harder. Just don't go nuts with it, like WOT full rev range pulls, lol. See if that will let the car rev smooth over 3-4k rpm.

By doing this, we can limit out the O2-sensor faults. Just be careful and don't go nuts.

It's starting to be night where I live. I will check forums right on the morning when I get to work. Good luck.

Hey bro, thanks for you long detailed response!

Okay so would you say my o2 sensors are looking okay from the logs?

Just to double check I’ll go out tomorrow when I get up and see what the Lamba Banks are saying on the MHD app are once I’ve been out for a cruise and the engine is hot and I’ll get back to you.

Okay good because I just spent so much on them new turbos bro lol, just want her to be running how she was start of this year. Had 0 issues up until recently. I need to get the bottom of it asap

My first initial thought would have been lpfp but I’m glad I come kn here before I started throwing money at her.

Okay, so it’s usually sputtering when I give it about 40-50% throttle. But if I just ease into it it will go but I’m trying not to even experiment anymore because I don’t want to break anything.

Tomorrow I’m gonna go to my mates garage give that trick a go with the precat sensors and see what happens and get back to you with tsome info as well bro.

That picture was clutch! Thanks bro really appreciate your help!

 

[odesh]

Hey bro, thanks for you long detailed response!

Okay so would you say my o2 sensors are looking okay from the logs?

Just to double check I’ll go out tomorrow when I get up and see what the Lamba Banks are saying on the MHD app are once I’ve been out for a cruise and the engine is hot and I’ll get back to you.

Okay good because I just spent so much on them new turbos bro lol, just want her to be running how she was start of this year. Had 0 issues up until recently. I need to get the bottom of it asap

My first initial thought would have been lpfp but I’m glad I come kn here before I started throwing money at her.

Okay, so it’s usually sputtering when I give it about 40-50% throttle. But if I just ease into it it will go but I’m trying not to even experiment anymore because I don’t want to break anything.

Tomorrow I’m gonna go to my mates garage give that trick a go with the precat sensors and see what happens and get back to you with tsome info as well bro.

That picture was clutch! Thanks bro really appreciate your help!

I wouldn't say that the O2-sensors are okay. Like I said, those kind of lean conditions would grenade the engine instantly, if the car even ran that lean. That lean would be way too little fuel to even drive the car.

The LPFP seems to be fine. On the first log it got little low, but nothing alarming.

And it is understandable that you don't want to drive the car to not break anything. So no worries there. If the O2-sensors are malfunctioning and are the cause of the issue, the car should run way smoother (not perfect obviously) on the open loop mode when they are unplugged.

 

[Tonynotoes]

I wouldn't say that the O2-sensors are okay. Like I said, those kind of lean conditions would grenade the engine instantly, if the car even ran that lean. That lean would be way too little fuel to even drive the car.

The LPFP seems to be fine. On the first log it got little low, but nothing alarming.

And it is understandable that you don't want to drive the car to not break anything. So no worries there. If the O2-sensors are malfunctioning and are the cause of the issue, the car should run way smoother (not perfect obviously) on the open loop mode when they are unplugged.

So the issue is fuel related from the logs. Okay that’s a good step in the right direction. That’s good to know.

Yeah I don’t know why that was. From the first few logs it was dropping to like 45psi and then just stopped strangely.

I can go out unplug the pre cats now. Need to get the engine cover off. I’ll let you know any updates. Thanks again bro

 

[AzNdevil]

Yeah you can only understand logs by trying to study them. It comes with time, so no worries. I try answer every question, let's see.

234 is the maximum lean condition that the sensor can read. When you let of the gas, it's normal to go that high since the injectors are not injecting any fuel at that moment since you are not demanding any power.

14-15 AFR on idle is totally normal. Usually when O2-sensors are out, the AFRs tend to creep up while idling when they get hot. But again, every case is different.

I wouldn't say you are over boosting. Idk where the other person got that idea. The boost target seems to be 15psi on stage 2 map and your logs seem to stay under that limit. The throttle closure happens (most likely) due to the missfire detection or lean condition detection. The engine is just trying to protect itself.

Does the car do that only on full out throttle acceleration or on lighter acceleration too? What I mean, does it do the same when you try to come to acceleration little softer?

If it does, you can try this: Since the turbos were replaced 5k ago, please check that the O2-sensors are plugged the right way, aka not mixed. If they are not mixed, unplug both precat O2-sensors. The connectors can be found on the top of engine, next to the fuel rail. This will put the car on the open loop mode regarding the O2-sensors. This same thing happens when you start the car when it's cold. I guess you can call it static mode. The car will just run rich. You can drive the car without it going to limp mode because you have the MHD flashed. Try driving the car softly and feel how it feels. Lock the gearbox to 2nd or 3rd gear so you have more control over what's happening. If it works on lighter throttle, you can try accelerating harder. Just don't go nuts with it, like WOT full rev range pulls, lol. See if that will let the car rev smooth over 3-4k rpm.

By doing this, we can limit out the O2-sensor faults. Just be careful and don't go nuts.

It's starting to be night where I live. I will check forums right on the morning when I get to work. Good luck.

first log shows overboosting and huge throttle closures but afr was fine

second log the car was overboosting and constantly under throttle closure

third log it wasnt overboosting as much and much less throttle closure but afr does look weird which might be caused by the throttle closure

fourth log which i just looked at..... traction control kicked in when this log was taken so...it doesnt really serve any purpose

throttle closure happens when boost > boost target unless disabled or tuned out and afr is one of the things that get affected when throttle closure kicks in cause you know, the car is lifting off the throttle.

throttle closure does not happen due to misfire detection. if it misfires enough times the car cuts the cyclinder ignition completely until its restarted.

@Tonynotoes take the log with traction control off

 

[Tonynotoes]

Thanks for that info @AzNdevil mate, will do that tomorrow.

I also haven’t had time to disconnect the precat sensors so will do that over the weekend and get back to you lot.

I’m really trying to resolve this issues as it’s making me want to sell the car and buy something else. Had this car 5 years probably spent about 10k on her now, just constantly spending money on her.. guess that’s the n54 life boys hahaha

 

[AzNdevil]

oh hell yea living the n54 life yo. these cars are cheap to buy but expensive to run long term.
depending how much/how hard you drive the car, major maintenance comes every at 3-5 years

honestly if you ask me, you aint that deep into the hole. the more mods you throw at it the more fun and painful it gets

bottom line, its a fun and relatively reliable car if you do preventive maintenance on it but the costs do get out of hand and they still break when you least expect it to. its not like you are going to be able to find another cheap car that can do ~400whp fbo