[maxrev30]

Hello everyone, its been awhile since I've had my m235i as my dad has been driving it for the past year. He told me its been having issues since he did a few bolt on's. So i decided to let him drive the rs3 while i figure out what is going on with the m235i. Today I've done a few data logs that I'd like to share. I believe the hpfp is either dying on me or being over worked, but I'm not sure yet.

I also believe there is an issue with either the torque converter as well. Even before all the bolt ons the transmission would stutter and felt pretty bad. Now the car has 120k miles on it and has never had a transmission fluid change which could definitely be causing the issue. I have oil and a new pan coming asap.

Ill start with a list of things done to the car.

Vrsf intercooler
Fuel it Flex fuel sensor
Vrsf catless downpipe
Upgraded intercooler piping
Newish (3k miles) ngk 1 step colder plugs
All new coil packs (3k miles)
I have brand new upgraded injectors but they're not installed
Bm3 stage 2 tune ots

Long story short the car will sometimes pull great or sometime have these huge hiccups or what feels like aggressive misfires. The first day i drove it after picking it up it felt pretty good, no real issues. So i messed around with all 4 of the multi maps to see if maybe what he was feeling was fuel related. On map 2 91 icould see more timing corrections and it felt stuttery compared to map 1. So i figured that was what he was seeing. I decided to throw e30 in the car and do some tests. The car was showing it had about e29 in it via the ethonal content sensor and i was using the stage 2 flex fuel tune. During a hard pull onto the freeway it had a massive issue accelerating as if it just fell flat on its face but with stutters. Unfortunately i didn't log it. Today the car is on 91 oct e15.

I did 3 logs a 3rd gear pull, 4th gear pull, and a 2nd-3rd gear pull.

During the 2nd-3rd it happened again.

I will upload each csv for people to look at. Please give me any ideas on what the best course of action would be. Also I'm horrible at reading logs so that's a big reason I'm coming to the forums for help.

Thanks!

2nd gear felt horrible
https://bootmod3.net/log?id=65fa111429b463058d0f01c8

3rd gear
https://bootmod3.net/log?id=65fa10d1173e641b538472b0

4th gear
https://bootmod3.net/log?id=65fa10e7675068059c610e94

[maxrev30]

Bump. Should i ask this in a different area? Any help would be greatly appreciated.

[designatedposter]

you're on the right track about the HPFP, can clearly see the HPFP can't keep up in the 2nd gear log, however, im surprised that your 3rd and 4h gear logs are less significant strain on the hpfp (still tough on it though). i'd try the boost limit feature to limit to a max of 16psi to reduce strain on fuel system and see if you still have issues.

[maxrev30]

Originally Posted by designatedposter

you're on the right track about the HPFP, can clearly see the HPFP can't keep up in the 2nd gear log, however, im surprised that your 3rd and 4h gear logs are less significant strain on the hpfp (still tough on it though). i'd try the boost limit feature to limit to a max of 16psi to reduce strain on fuel system and see if you still have issues.

I didn't even know the boost limit feature was a thing. I will give that a try, any idea on what a good recommendation would be for a new hpfp?

Thanks

[designatedposter]

since you already have the flex fuel sensor, the next logical step is a "stage 1" hpfp if you stay stock turbo. then you'd be able to use the stage 2+ map which is a significant bump in power and run any amount of ethanol you please (with increased power).

go "stage 2" hpfp if you plan to upgrade turbo.

popular brands of hpfp: dorch, spool, xdi, precision raceworks

[maxrev30]

Originally Posted by designatedposter

since you already have the flex fuel sensor, the next logical step is a "stage 1" hpfp if you stay stock turbo. then you'd be able to use the stage 2+ map which is a significant bump in power and run any amount of ethanol you please (with increased power).

go "stage 2" hpfp if you plan to upgrade turbo.

popular brands of hpfp: dorch, spool, xdi, precision raceworks

Awesome thank you for the information! I wil start digging around for pricing.

[E90lova]

I have the same issue and am also at just over 120k miles.

[maxrev30]

Originally Posted by E90lova

I have the same issue and am also at just over 120k miles.

Mine was 100% related to fuel pump. I replace with the dorch stage 1.5 and put the m5 injectors in and the issue went away completely. I was able to load the stage 2+ tune and i only have some timing corrections which i sure will go away with better fuel since i only have access to 92oct. I'll be ordering a barrel of e85 soon and will see how it runs on full E.