[eluzbet]

Hey everyone,

Looking for some insight on a persistent timing correction issue with my 2007 BMW E93 335i (N54). The car is tuned and running an MHD Stage 2+ map with supporting mods (also tested Stage 0 — no difference). I've ruled out the usual suspects and would really appreciate help reviewing my logs.

Mods

FMIC: 5.5” stepped intercooler

Charge pipe with Tial BOV

Dual cone intakes

Catless downpipes

Upgraded LPFP

NGK 97506 plugs gapped to 0.020–0.022”

Running 93 octane, no ethanol

Walnut blast already done

All index 12 injectors

Timing Correction Issue
Getting timing corrections on all cylinders (mostly -3 to -5°, sometimes -6°)

Happens under both light and WOT

Tried flashing Stage 0 — still happening

No fault codes related to ignition or misfire

Doesn’t feel like knock — car runs smooth, but corrections are always there


I have already rules out plugs, tune, and fuel quality, if you have any ideas please let me know.
Here are some logs
https://datazap.me/u/eluzbet/timing-...og=0&data=3-22

https://datazap.me/u/eluzbet/timing-...og=0&data=3-22

[Sgop335]

Its high iat and high boost w not enough octane. Not much one can do w/o ethanol or octane booster like klotz.
Side note bank 2 may have leaky injector

[eluzbet]

Originally Posted by Sgop335

Its high iat and high boost w not enough octane. Not much one can do w/o ethanol or octane booster like klotz.
Side note bank 2 may have leaky injector

Wouldn’t a stock map fix it cause of low boost? I get the same corrections with the factory tune. This also just started happening after about 2 years of the car running smooth with the same mods.
Also thanks for the clarification on bank 2 I saw the afr wasn’t on par with bank 1 but didn’t know why

[Sgop335]

Iats are still quite high. may be spark plugs are older / deposits

[eluzbet]

weird, plugs are brand new only have 100 miles and i did a walnut blast about 10k miles ago

[Sgop335]

guess no substitute for octane and iat.

[eluzbet]

Originally Posted by Sgop335

guess no substitute for octane and iat.

Ill try ethanol and see what happens

[lowrydr310]

It may be injector related, I had similar timing corrections despite brand new plugs and coils and a fresh walnut blast. I had no obvious signs of injector leaks, pulled all the plugs after sitting overnight and all cylinders were dry. I even ran a tank of 100 octane with the stock tune and still had these corrections.

I did have some significant discrepancies between each bank on the fuel trims which had me focusing on injectors. After replacing them all (4 brand new, 2 used which were sent off for cleaning and testing to confirm flow) there are no more timing corrections.

[eluzbet]

Originally Posted by lowrydr310

It may be injector related, I had similar timing corrections despite brand new plugs and coils and a fresh walnut blast. I had no obvious signs of injector leaks, pulled all the plugs after sitting overnight and all cylinders were dry. I even ran a tank of 100 octane with the stock tune and still had these corrections.

I did have some significant discrepancies between each bank on the fuel trims which had me focusing on injectors. After replacing them all (4 brand new, 2 used which were sent off for cleaning and testing to confirm flow) there are no more timing corrections.

Yeah this sounds very similar to my situation i’ll definitely check out the injectors, thank you

[lookalikehuuh]

A couple of things to note, you are running 2 step colder plugs, I wouldn't recommend running the colder plugs unless you have hybrid turbos, or single turbo. I have personally found (while dealing with california ACN91 octane) that the OE bosch spark plugs were much better with timing corrections.

Others are saying that your IATs are high, but they are under 120F, yes of course cooler is better but you also live in Florida... so 100F IATs are not going to be uncommon.


A few critical questions:

1. What brand is your 5.5" Stepped IC?

2. What brand fuel are you using?

3. Have you tried the 91 octane tunes to see what the timing corrections are like there?

4. Have you tried to run a couple of bottles of Chevron Techron thru the fuel system?

[eluzbet]

Originally Posted by lookalikehuuh

A couple of things to note, you are running 2 step colder plugs, I wouldn't recommend running the colder plugs unless you have hybrid turbos, or single turbo. I have personally found (while dealing with california ACN91 octane) that the OE bosch spark plugs were much better with timing corrections.

Others are saying that your IATs are high, but they are under 120F, yes of course cooler is better but you also live in Florida... so 100F IATs are not going to be uncommon.


A few critical questions:

1. What brand is your 5.5" Stepped IC?

2. What brand fuel are you using?

3. Have you tried the 91 octane tunes to see what the timing corrections are like there?

4. Have you tried to run a couple of bottles of Chevron Techron thru the fuel system?

Hello so I only switched to the colder plugs cause i was getting the same corrections with the OE Bosch plugs and wanted to rule the plugs out,
1. It’s vrsf
2. I’ve had the corrections for a while now so i’ve tried about every brand of fuel out there and I get the same results.
3. I haven’t tried the 91 octane tunes but I have tried octane booster
4. No i have not

[lookalikehuuh]

Originally Posted by eluzbet

Hello so I only switched to the colder plugs cause i was getting the same corrections with the OE Bosch plugs and wanted to rule the plugs out,
1. It’s vrsf
2. I’ve had the corrections for a while now so i’ve tried about every brand of fuel out there and I get the same results.
3. I haven’t tried the 91 octane tunes but I have tried octane booster
4. No i have not

Yep that sounds like you probably have something going on with atomization with fuel most likely. Next time you fill up drop a bottle of techron in the fuel tank then fill the car up. Do it again after that tank is gone thru. ensure you fill up with Shell or Chevron to ensure you have high quality fuel in there.

[eluzbet]

Originally Posted by lookalikehuuh

Yep that sounds like you probably have something going on with atomization with fuel most likely. Next time you fill up drop a bottle of techron in the fuel tank then fill the car up. Do it again after that tank is gone thru. ensure you fill up with Shell or Chevron to ensure you have high quality fuel in there.

Awesome, Will do thank you!

[eluzbet]

update, techron did not work, i will be replacing leaky injectors and getting them all reconditioned soon

[eluzbet]

update,
Injectors did not work, They were flow and leak tested as well as cleaned. I also swapped the banks and see no differences in logs. Idle stumble is gone but that is about it.

new log
https://datazap.me/u/eluzbet/test-4-...2.45&tmax=4.00

I have no clue what's wrong.

[Cannonfodda101]

did you replace your intake manifold gasket after the walnut blast?

[eluzbet]

Originally Posted by Cannonfodda101

did you replace your intake manifold gasket after the walnut blast?

Yes I replaced all 6 seals

[acidbbg]

Run ethanol. Almost certainly will fix timing corrections.

Experimented with 2 n54 1 run Cobb tune and other MHD. Tried 100 octane and still had corrections. Run fuel treatment but same issue. Ran a couple gallons of ethanol on top of top tier 93 fuel and both cars timing corrections dropped instantly!

[eluzbet]

update, i added about 2.5 gallons of e85 this left me at around e20.
Timing corrections seemed to have gotten better and maybe a be more infrequent, However they are still there and there are times where all 6 cylinders pull timing from around -0.5 to -3, and there are times where one cylinder will pull -7 degrees.
This is on a 93 stage 2+ mhd tune with ~20% ethanol.
Here are some before and after logs.

93 Octane only
2nd-3rd gear
https://datazap.me/u/eluzbet/test-1-...-10-22&mark=26
3rd-4th gear
https://datazap.me/u/eluzbet/test-4-...-6-7-8-9-10-22

~20% Ethanol on 93 tune
3rd-4th
https://datazap.me/u/eluzbet/e20-93-...-6-7-8-9-10-19
https://datazap.me/u/eluzbet/e20-93-...-6-7-8-9-10-19

Originally Posted by acidbbg

Run ethanol. Almost certainly will fix timing corrections.

Experimented with 2 n54 1 run Cobb tune and other MHD. Tried 100 octane and still had corrections. Run fuel treatment but same issue. Ran a couple gallons of ethanol on top of top tier 93 fuel and both cars timing corrections dropped instantly!

[lookalikehuuh]

Very important: did you test the e85 for actual ethanol content? I ask this becuase its winter time, and in the winter E85 can be as little as 51% or up to 83% ethanol straight from the pump. This varies wildly based on location as they adjust the formulation based on the local climate. This is because its MUCH more difficult to start on E85 when its near freezing temps outside vs a mix closer to E51.

I live in socal, and we never get cold enough where our ethanol ever gets dropped below E80, but I was constantly testing my ethanol the first year before every fill up. I used a tester like this:
https://www.amazon.com/REV-X-Super-T...s%2C202&sr=8-7

The fact that your timing corrections got better is definitely a sign of poor quality fuels potentially exaserbating the condition. I would try going up to a real E30 mix to see if that eliminates all timing corrections entirely.

Did you ever end up going back to the OE Bosch plugs? I too once jumped into the NGK colder plugs bandwagon and I saw timing corrections even on E50 mix. After I went back to the Bosch OEs I see a timing correction every once in a blue moon.

[eluzbet]

I did not test, however I've tested this station before dozens of times and it's never been below 83-85%. I can go back and test. I'm also in South Florida so it doesn't get too cold.
I also have not gone back to the OE Bosch plugs, When the timing corrections started I was on Bosch plugs and that's why I switched to NGK to see if it would help. Once they are due again I'll be switching back.

Originally Posted by lookalikehuuh

Very important: did you test the e85 for actual ethanol content? I ask this becuase its winter time, and in the winter E85 can be as little as 51% or up to 83% ethanol straight from the pump. This varies wildly based on location as they adjust the formulation based on the local climate. This is because its MUCH more difficult to start on E85 when its near freezing temps outside vs a mix closer to E51.

I live in socal, and we never get cold enough where our ethanol ever gets dropped below E80, but I was constantly testing my ethanol the first year before every fill up. I used a tester like this:
https://www.amazon.com/REV-X-Super-T...s%2C202&sr=8-7

The fact that your timing corrections got better is definitely a sign of poor quality fuels potentially exaserbating the condition. I would try going up to a real E30 mix to see if that eliminates all timing corrections entirely.

Did you ever end up going back to the OE Bosch plugs? I too once jumped into the NGK colder plugs bandwagon and I saw timing corrections even on E50 mix. After I went back to the Bosch OEs I see a timing correction every once in a blue moon.

[Gizm0]

You're targetting 18.6psi with stock turbos, they will produce a lot of heat. Doesn't help that you are in FL. Even if you have an upgraded FMIC, it will knock and pull timing unless you either reduce the boost target, or get higher octane fuel.

2.5 gallons of E85 in a 16 gallons tank will get you an octane rating of 95. That's assuming the ethanol is actually E85, and assuming good quality 93 octane gas, but as mentioned above, during winter, the ethanol content is most likely lower. If the ethanol is only E70, and you get gas from a shitty gas station, I wouldn't be surprised if you end up with even lower octane than 93, even with 2.5 gallons of E70. Up your ethanol content a little, I usually put about 4 gallons in mine during the winter to end up with E30 mix, and it pulls hard with no timing corrections, boost target is 19psi.

Also if you always get gas from the same gas station, try switching up. Where I live for example, I found out that Shell was causing timing pulls like yours, but gas from Sams Club out of all places worked much better with minimal timing corrections.