[AlexGT]

I've been trying to troubleshoot an issue where going full WOT I experience hesitation and stutter, mainly when full WOT happens between 900 and 1000 RPMs (at higher RPMs, I don't have any problems in full WOT). No codes whatsoever shown on the iDrive nor when using a scanner....

So far I've replaced these parts for brand new OEM ones trying to resolve the problem:

- Injectors
- MAF Sensor
- MAP Sensor
- Spark Plugs
- Ignition Coils

But the stuttering remains.....

I've told that it might be the Fuel Pump Control Unit (part number 16149494391 for the B48 engine), but, I don't have any codes showing that the module has a problem. Should this part throw a code if it is malfunctioning or could it be having problems without throwing any codes?

Thanks for the help as I've been trying to resolve this stuttering and hesitation when I WOT between 900-1000 rpms for six months now

[BMWILUVU]

1000k rpms? Helluva engine! Did you have it checked for vacuum leak?

[AlexGT]

Originally Posted by BMWILUVU

1000k rpms? Helluva engine! Did you have it checked for vacuum leak?

LOL, sorry I meant 1000 (or 1K) RPMS

[njdangelo]

Originally Posted by AlexGT

I've been trying to troubleshoot an issue where going full WOT I experience hesitation and stutter, mainly when full WOT happens between 900K and 1000K RPMs (at higher RPMs, I don't have any problems in full WOT). No codes whatsoever shown on the iDrive nor when using a scanner....

So far I've replaced these parts for brand new OEM ones trying to resolve the problem:

- Injectors
- MAF Sensor
- MAP Sensor
- Spark Plugs
- Ignition Coils

But the stuttering remains.....

I've told that it might be the Fuel Pump Control Unit (part number 16149494391 for the B48 engine), but, I don't have any codes showing that the module has a problem. Should this part throw a code if it is malfunctioning or could it be having problems without throwing any codes?

Thanks for the help as I've been trying to resolve this stuttering and hesitation when I WOT between 900-1000 rpms for six months now

Were the MAF and MAP sensors legit OEM or were they Chinese? The sensors in these cars absolutely need to be OEM/Bosch or the car won't run right. If so then it could be an issue with the wastegate. Can you do some data logs? It could also be the engine pulling timing but we would need to see logs to assess why.

[AlexGT]

Originally Posted by njdangelo

Were the MAF and MAP sensors legit OEM or were they Chinese? The sensors in these cars absolutely need to be OEM/Bosch or the car won't run right. If so then it could be an issue with the wastegate. Can you do some data logs? It could also be the engine pulling timing but we would need to see logs to assess why.

Thanks so much for the reply man. Yes, all parts that I’ve replaced are authentic as they were purchased at ECS Tuning. To be very honest, I don’t know how to pull data logs... let’s say that it could be the wastegate, that part can be malfunctioning and not throwing codes? I’ve seen that my wastegate does not retracts immediately after releasing the gas pedal, is that a normal behavior? Please look at the video

https://youtu.be/3Va1NFG6eQU

[njdangelo]

Originally Posted by AlexGT

Thanks so much for the reply man. Yes, all parts that I’ve replaced are authentic as they were purchased at ECS Tuning. To be very honest, I don’t know how to pull data logs... let’s say that it could be the wastegate, that part can be malfunctioning and not throwing codes? I’ve seen that my wastegate does not retracts immediately after releasing the gas pedal, is that a normal behavior? Please look at the video

https://youtu.be/3Va1NFG6eQU

Looks like it is functioning normally the timing does seem a little weird but that is controlled by the engine computer based on the info it's getting from sensors and it seems to be responding normally. It doesn't look loose or stuck. To do logs you'll need a tuning software like bm3 or mhd, or you'll need to go to a mechanic.
In my opinion all of the info is starting to point to a vacuum or PCV issue. I had a very similar issue in an A4 I used to own where it would stutter under load between 1k-2k. I brought it to about 6 different mechanics, Indy, Audi, tuners, and no one could ever find the problem. I tried EVERYTHING to fix it. The only thing that worked, and it was only fixed it for about 3 months, was installing a new intake manifold. Sold the car after 4 years to my coworker who is still driving it without any advancement on the issue.
In that particular instance there was definitely negative pressure in the engine because when I would remove my oil cap with the engine running there would be a tremendous amount of suction trying to bring the cap back down. No idea where the pressure was coming from. I learned to just live with it and only go WOT after 2k rpm lol.
To this day it bothers me that I could never figure it out.

[drdino]

Is the suttering a new development or has it always been there ? Going wot at 900rpm is bound to be a bit messy on my opinion, that's basically fast idle. How had does it stutter?

[floridaorange]

take it in

[Pjhanna89]

Sorry to Hijack, don't have anything to add to original post, new user and can't start new thread myself, but some of the same symptoms. 2017 320i (b48), 33k miles and 9/10k OCI kept up in its life so far running an eco map around 220ps, for last 3k miles/4 months with no issues until this week. Rough running, idling and vibration diagnosed as a misfire in cylinder 1 at main dealer. Coils swapped and all spark plugs changed and problem remains on cylinder 1. Dealer is holding on to car for a week or so due to workload but wondering if anyone has had similar issue and what I might expect them to find and if there's any possibility the map could have contributed to the issue? Many thanks

[AlexGT]

Originally Posted by Pjhanna89

Sorry to Hijack, don't have anything to add to original post, new user and can't start new thread myself, but some of the same symptoms. 2017 320i (b48), 33k miles and 9/10k OCI kept up in its life so far running an eco map around 220ps, for last 3k miles/4 months with no issues until this week. Rough running, idling and vibration diagnosed as a misfire in cylinder 1 at main dealer. Coils swapped and all spark plugs changed and problem remains on cylinder 1. Dealer is holding on to car for a week or so due to workload but wondering if anyone has had similar issue and what I might expect them to find and if there's any possibility the map could have contributed to the issue? Many thanks

Please wait until you have access to create a thread as this is NOT the same problem. Hijacking threads is not polite

[AlexGT]

Originally Posted by drdino

Is the suttering a new development or has it always been there ? Going wot at 900rpm is bound to be a bit messy on my opinion, that's basically fast idle. How had does it stutter?

It's been like this for the last 6 months.

Here's a video the BMW dealership took after they replaced the injectors (after they said it might me a problem with the injectors) and the issue remains.

https://youtube.com/shorts/wlQf4whbAhk?feature=share

[drdino]

I'll try it on mine if I get the chance. Revving while stationary is not really representative though, does it cause any actual drivability issues?

[AlexGT]

Originally Posted by drdino

I'll try it on mine if I get the chance. Revving while stationary is not really representative though, does it cause any actual drivability issues?

Are you having the same issue as I? You say you'll try it on yours if you get the chance, sorry I didn't understand what you meant.

Drivability issues just when WOT between 900-1000RPMs, the issue actually does not happen at all on higher revs when WOT and strangely does not happen when accelerating smoothly (not WOT) between 900-1000RPMs.

[drdino]

I don't have the issue no, I can compare it to my 330i with the B48 to confirm if it's an issue or not. To be honest, that particular rev point is really not useful and it might be that it's where a changeover in the calibration maps happens.

[AlexGT]

Originally Posted by drdino

I don't have the issue no, I can compare it to my 330i with the B48 to confirm if it's an issue or not. To be honest, that particular rev point is really not useful and it might be that it's where a changeover in the calibration maps happens.

Thanks but I'm sure you don't have the issue, as it is very noticeable. The issue started six months ago (didn't have it before). Six months with a huge question mark in my head, wondering what the hell is making my B48 to have this weird behavior.

[drdino]

Have you made any logs? Throttle pedal/throttle, fuel pressure, ignition advance, any misfires/knocks etc?

[thejeremyman9]

Is your car completely stock or tuned? If its tuned, definitely datalog the problem.

If its completely stock, are you forcing the engine to stay low RPM for the problem to occur? I don't see any other way you would be WOT at <1k RPM except in 1st gear from a dead stop as the car would almost certainly downshift before it starts to build any significant boost or load at that low of RPM.

[AlexGT]

Originally Posted by drdino

Have you made any logs? Throttle pedal/throttle, fuel pressure, ignition advance, any misfires/knocks etc?

Nope, don’t know how to pull and save logs tbh

[AlexGT]

Originally Posted by thejeremyman9

Is your car completely stock or tuned? If its tuned, definitely datalog the problem.

If its completely stock, are you forcing the engine to stay low RPM for the problem to occur? I don't see any other way you would be WOT at <1k RPM except in 1st gear from a dead stop as the car would almost certainly downshift before it starts to build any significant boost or load at that low of RPM.

Stock map, but it does have MST intake, VRSF downpipe and aluminum charge pipe. And the problem appeared before getting those parts installed

[thejeremyman9]

Originally Posted by AlexGT

Stock map, but it does have MST intake, VRSF downpipe and aluminum charge pipe. And the problem appeared before getting those parts installed

First thing to test IMO is going back to stock intake but you said it started before that...

So are you in manual mode when it happens or auto?

[AlexGT]

Originally Posted by thejeremyman9

First thing to test IMO is going back to stock intake but you said it started before that...

So are you in manual mode when it happens or auto?

Thanks but as I said, the problem started before replacing those parts (we did a test with stock parts, same issue).

I always drive in auto mode, but the issue lowers when driving auto in sport mode as the sport mode revs a little bit more the engine so when cruising at lower speed, revs keep above 1k rpms.

[paulymu]

I want to say my car is doing something similar, but my car does it on start ups and sometimes when i'm at like a traffic light. It been like this since i bought the car but it wasn't as obvious. It was always so slight that it could go unnoticed. The worst its been is when i got the DME and took it to the dealer and they said it was the vent valve and i replaced it and the issue went away but its back. Plan on taking it back to the dealer and see what they say this time. Strange thing is i have no cel or anything. Don't feel like giving bmw another $180 for diagnosis but i'm over it at this point. Mite take it to a local mechanic first and see if they can diagnosis it first. This and an issue with my window directional switch button being stuck in one position causing my left side mirror to pan out and make it difficult to see out of are my only current issues. Soon have it all taken care of though.