16' M4 FBO, GC Turbos - misfires @ 6400+

[TopJimmy]

The other fix...take those Spool HPFPs off and the tune you have updated from Cary should rip.

If you have a shop it's no biggie...I was elbows deep pulling the rail so I could swap out an injector...and it was work done freezing cold and windy in my driveway over the last couple days.

+1+1+1 on Commanderwiggin plug recommendation above! I used that same from a PM he sent me and my authentic BMW (NGK F8S) flex-fuel plug arrived today.

[belittle]

Little update.

Got the ethanol analyzer up and running this afternoon. Looks like my last fill up was actually an E54 blend..... Threw 2 gallons of 91 in to get it down to E30, ripped through the RPM band with no misfires. Highest airflow reading so far with what seems to be no upper RPM fueling issues. Rock solid AFR's, You can see the pumps doing work at the lower RPMs for sure, can tell I need the target threshold error turned tuned so I will need something custom is clean it up.

1st log:
https://www.bootmod3.net/log?id=5fea...90c67c6b366ec3

2nd Log:
https://www.bootmod3.net/log?id=5fea...0b431a1b66b390

Thinking I'm going to just ditch my last custom tune and go with a blend that is a little lower then straight E85. Looking at the E85 logs vs. E30, fuel pressures are almost 500 psi lower in the upper RPM. Feel like E50 w/ the spool setup gives alot of margin for maxing out the stock block.

[belittle]

Originally Posted by Commanderwiggin

Looking at the logs it's clearly out of fuel...the Spool HPFP's are only going to help out with midrange fueling...the injectors are tapped out up top. Need to upgrade the injectors if you want more power (Or additional fueling via meth/PI). Your E30 OTS tune is higher load than the car can handle and if you want to wreck your car, keep running with those misfires lol. Whoever the tuner is likely knows what the issue is and yes it will cost money if you want to change your current custom tune...he fixed the first one already and told you you're out of fuel. Why would he lie lol. The LPFP is not the issue...the HPFP is not the issue. But feel free to spend 3k on pumps and not ask your tuner lol.

Tuner gave me 4 revisions, all misfiring. If he 'knew' the issue why did he continually send revisions that ran like shit? In my head, you'd want to maybe not start at MAX + misfires and maybe work your way up? My last revisions was a desperate cry for my sanity (and safety) to get something that was 'driveable' and wasn't going to blow my engine up. I was given finally something that you could tell was watered down.

When I asked about the spool setup + M5 injectors it was a good recommended setup. Just need to pay more $$ to tune with it.

[papasmurf_m3]

Glad you got it fixed! Be careful with those misfires.

[jpy1980]

Originally Posted by papasmurf_m3

Glad you got it fixed! Be careful with those misfires.

Quick Q. Besides looking at logs, what does an actual misfire feel like? Like a stutter? Sputter?

[papasmurf_m3]

Originally Posted by jpy1980

Quick Q. Besides looking at logs, what does an actual misfire feel like? Like a stutter? Sputter?

Stiffer with an audible noise, it could be loud or it could be quite but you will feel it miss.

[Sejo5]

I had that sputter as well on E50 cause of Fuel.. once i went PI everything was smooth Sailing on E85.

[///BMW Junkie]

Originally Posted by belittle

Tuner gave me 4 revisions, all misfiring. If he 'knew' the issue why did he continually send revisions that ran like shit? In my head, you'd want to maybe not start at MAX + misfires and maybe work your way up? My last revisions was a desperate cry for my sanity (and safety) to get something that was 'driveable' and wasn't going to blow my engine up. I was given finally something that you could tell was watered down.

When I asked about the spool setup + M5 injectors it was a good recommended setup. Just need to pay more $$ to tune with it.

Who recommended this setup?

[MisterF80M3]

I'm still having the same issue since November. I just got fresh flex-fuel plugs installed gapped to .020 and it is still misfiring at 6000+RPM

[///BMW Junkie]

Originally Posted by MisterF80M3

I'm still having the same issue since November. I just got fresh flex-fuel plugs installed gapped to .020 and it is still misfiring at 6000+RPM

Tuner?
Post logs

[StockM4]

Im having this issue with vargas gc turbos...not throwing codes though, but it misfires in 3rd gear when trying to do a 60roll. Car was running amazing yesterday n pulling hard. But all of a sudden this started happening today.
Brand new 2step colder plugs installed less then 2k miles.