[00866b]

Hi guys my names Besher. This lowkey my first post but since I'm already half way FBO into my F10 535i I said f it lemme sign up and be with the community .

So here's a little back story about my lovely F10.
Bought it in March 2022 no problems then DTM came dealer said it was a bad plug or coil I don't remember they replaced it and nothing happened ever since .

Fast forward to today . I'm pretty much half way into FBO
-VSRF cattless DP
-MST RE-LOCATED intake
- charge pipe
- ofc straight piped
- stage 2 E85 tuned with BM3
- Stage 4 XHP tuned
- 6 Gallons of E-85 + rest 91 octane

So now that I got my upgrades out of the way , here's the problem : just recently only when I would put it in S transmission it would stutter when I hard floor it/ Accelerate. Then slowly but surely it kept happening more and more til yesterday I came back from my work job at 3 am and in my head I was like f it lemme floor it. Yk how I said if I pushed it hard / under load it would stutter / hesitate ? Well now I decided to not let go of the pedal while it was stuttering and before Yk it , for the first time it gave me a DTM rpm's starts going up and down crazy and when I finally made it home thank god it happens less then .2 mile away from my home , and I holded the break, it kept pressing gas or wanting to accelerate so I panicked and turned it off .

Turned it on within 5 mins afterwards ,,, DTM came in for a split second plus the engine light then they all turned off it's like nothing happened ?

I did my research and saw it was probably you know bad plugs … I went and gotten NGK Laser Iridium
SILZKBR8D8S Spark Plug ,,, replaced all 6 of them for the first time ever my self ,, took it for a run although it did sound crispy and loud and more pops , when I put it into s transmission it lwokey tried to stutter again .
My theory is since this thing full bolt on I think it could probably be either
-Plugs (already replaced)
- COILS (going to buy the PR Ignition coil kit $400)
And see if that helps
- Or injectors .
If not for some what ever reason I think my downpipe clogged maybe too much burbles ? Because I noticed how the exhaust note stated sounding not so crispy .

Ik for a fact it's not my fuel pump not the HPFP OR LPFP because yes I did datalog everything ok BM3 and they seem to be alright *
Here's my recent bm3 data log after I replaced my plugs : https://www.bootmod3.net/log?id=633c...729b65688818c3

Here's my bm3 log from October 3 : https://www.bootmod3.net/log?id=633b...90c63171d23f5e
And here's is my bm3 log from September 30: https://www.bootmod3.net/log?id=6332...90c63171d219f7

Can someone tell me if there's any pattern? Thank you . I'm still fairly new to the car modding world , first ever project car only 18 so any knowledge help because I install everything my self .

[00866b]

Originally Posted by 00866b

Hi guys my names Besher. This lowkey my first post but since I'm already half way FBO into my F10 535i I said f it lemme sign up and be with the community .

So here's a little back story about my lovely F10.
Bought it in March 2022 no problems then DTM came dealer said it was a bad plug or coil I don't remember they replaced it and nothing happened ever since .

Fast forward to today . I'm pretty much half way into FBO
-VSRF cattless DP
- charge pipe
- ofc straight piped
- stage 2 E85 tuned with BM3
- Stage 4 XHP tuned

So now that I got my upgrades out of the way , here's the problem : just recently only when I would put it in S transmission it would stutter when I hard floor it/ Accelerate. Then slowly but surely it kept happening more and more til yesterday I came back from my work job at 3 am and in my head I was like f it lemme floor it. Yk how I said if I pushed it hard / under load it would stutter / hesitate ? Well now I decided to not let go of the pedal while it was stuttering and before Yk it , for the first time it gave me a DTM rpm's starts going up and down crazy and when I finally made it home thank god it happens less then .2 mile away from my home , and I holded the break, it kept pressing gas or wanting to accelerate so I panicked and turned it off .

Turned it on within 5 mins afterwards ,,, DTM came in for a split second plus the engine light then they all turned off it's like nothing happened ?

I did my research and saw it was probably you know bad plugs … I went and gotten NGK Laser Iridium
SILZKBR8D8S Spark Plug ,,, replaced all 6 of them for the first time ever my self ,, took it for a run although it did sound crispy and loud and more pops , when I put it into s transmission it lwokey tried to stutter again .
My theory is since this thing full bolt on I think it could probably be either
-Plugs (already replaced)
- COILS (going to buy the PR Ignition coil kit $400)
And see if that helps
- Or injectors .
If not for some what ever reason I think my downpipe clogged maybe too much burbles ? Because I noticed how the exhaust note stated sounding not so crispy .

Ik for a fact it's not my fuel pump not the HPFP OR LPFP because yes I did datalog everything ok BM3 and they seem to be alright *
Here's my recent bm3 data log after I replaced my plugs : https://www.bootmod3.net/log?id=633c...729b65688818c3

Here's my bm3 log from October 3 : https://www.bootmod3.net/log?id=633b...90c63171d23f5e
And here's is my bm3 log from September 30: https://www.bootmod3.net/log?id=6332...90c63171d219f7

Can someone tell me if there's any pattern? Thank you . I'm still fairly new to the car modding world , first ever project car only 18 so any knowledge help because I install everything my self .

Here is the pic how how I knew when it threw me the DTM and CEL that it was misfiring

[beamerguy707]

I would recommend checking your fuel injectors, checking coil packs, and check for any possible vacuum lines with a smoke machine. IMO I really think it's fuel injectors because of your ethanol tune because if you get bad ethanol gas or anything it can cause clogging in the fuel injectors

[00866b]

Originally Posted by beamerguy707

I would recommend checking your fuel injectors, checking coil packs, and check for any possible vacuum lines with a smoke machine. IMO I really think it's fuel injectors because of your ethanol tune because if you get bad ethanol gas or anything it can cause clogging in the fuel injectors

It only happens sometimes , when I push it under hard acceleration. So I was going to get a PR ignition kit coils ($400) n see if that does something or should I just save up and replace fuel injection manifold then coils ? Already replaced the coils and saw a huge difference.

[beamerguy707]

Yeah definitely save up and I would start with fuel injectors first because if you end up getting bad e85 from a gas station it can cause injector clogging, and those are the exact symptoms of a fuel injector being clogged where the car hesitates and stutters to give power right away.

[00866b]

Originally Posted by beamerguy707

Yeah definitely save up and I would start with fuel injectors first because if you end up getting bad e85 from a gas station it can cause injector clogging, and those are the exact symptoms of a fuel injector being clogged where the car hesitates and stutters to give power right away.

The thing is that I failed to say when I was making this lost , I just got into e-85 on October first ..,
This was happening way before e-85. I doubt it is anything to do with that ,,, and my hpfp and lpfp on my statistic when I record while driving showing normal like values ? I only put 4 gallon no more no less .

[beamerguy707]

How many miles are on your car?

[00866b]

Originally Posted by beamerguy707

How many miles are on your car?

64k

[beamerguy707]

Okay my best bet would definitely look into getting those coil packs changed out, do a smoke test on those vacuum lines for any possible leaks, knock out those fuel injectors, check your intake manifold sensor as that tends to get really dirty, and change mass air flow sensor!