[HeyTeeee]

Hello All. Posting here bc the car is on factory tune and I feel it would be silly to post in the MHD thread since I’m not running any ots/custom tunes. The corrections have somehow gotten worse after several maintenance tasks. First log is the cleanest one I’ve gotten so far and the only difference I can see is that, it was real cold that day.. Second log is after: All injectors swapped, vc+gasket swapped (had that nasty howling noise), fp regulator, pre cat o2 sensor, swapped out maf and map on intake mani (had a 28A0 code), hpfp was replaced before the first log, has 5”stepped hd vrsf fmic. Ltfts show car is running rich -5, -8 range so within the ok zone. Hoping yall can see something I don’t bc I would think corrections should be improving.



“Cleanish Log”
https://datazap.me/u/heyteeee91/log-...42-43-44-45-46

https://datazap.me/u/heyteeee91/log-...45-46-47-48-49

[twinscrolled]

Why did you change the injectors? Were they coded? Mileage on plugs and coils? What type of fuel? Any current check engine light? You are way too lean IMO for about half of that first WOT pull in the first log.

[HeyTeeee]

Plugs n coils are about 7 months old that was the very first maint item I did when I bought the car also 7 months ago. Gas is 92 in Oregon both runs are using Shell. I did the injectors for a variety of reasons, learning exp, it’s a used car and came with vrsf cp so who knows what’s been done etc but it sure runs a hell of a lot smoother than before I swapped them but still has some misfire action happening at idle/very low rpm 900-1.2ishk but runs strong after. Coded them with protool*

[HeyTeeee]

I’ve seen some Canadian logs which I guess have shit gas? Have much cleaner logs so that to me rules out gas quality unless OR has shit 92. I also read through someones post from Australia with scorching iats have minimal corrections which again to me rules out iat. Rail pressure seems fine so I haven’t bothered pulling up pump to test pressure since there isnt a low sensor. No codes and no ses lights so I’m hoping someone can help me learn what I’m missing

[twinscrolled]

Weird thing to do as N55 injectors rarely fail.

Anyway, the corrections are definitely no good. I would try adding some NOS octane booster (it will boost octane a full point), Torco, or a couple of gallons of E85 and do a log and see what the corrections are then.

[Supermoon]

Don't fix what ain't broke. Did you look into the intake ports?

[Bullcitybmmer]

Originally Posted by HeyTeeee

Plugs n coils are about 7 months old that was the very first maint item I did when I bought the car also 7 months ago. Gas is 92 in Oregon both runs are using Shell. I did the injectors for a variety of reasons, learning exp, it’s a used car and came with vrsf cp so who knows what’s been done etc but it sure runs a hell of a lot smoother than before I swapped them but still has some misfire action happening at idle/very low rpm 900-1.2ishk but runs strong after. Coded them with protool*

If you're willing to take the hit to your wallet, I'd give a fresh set of plugs & coils a shot. My car, for whatever reason, is super sensitive to plugs, and has flat out rejected a couple of sets of brand new, properly gapped, plugs. I bit the bullet a while back and just bought a full set of both from FCP Euro, and I trade them out for new ones every few months with their lifetime warranty program.

I wouldn't think that your plugs & coils are already shot after a few months, but it's the easiest thing to check and rule out.

[twinscrolled]

Don't diagnose by parts replacement.

[HeyTeeee]

It’s crossed my mind quite a few times. I’m considering getting the Precision Raceworks coils sometime in the future after the logs are all cleaned up. Anyone know if the Scwaben scanner will display spark waveform? Protool shows the durations but doesnt look like the Bentley manual examples

[SoCal_BMW_LA]

Possibly faulty DME.....
Or maybe it needs a update. 🤔
What spark plugs are you using?
And what's the gap?

[HeyTeeee]

Originally Posted by xavier1228

Possibly faulty DME.....
Or maybe it needs a update. 🤔
What spark plugs are you using?
And what's the gap?

That would suck so much ass lol Mhd shows current software as: 8615764. I have not looked into dme updates except when the 28a0 code was lingering around but that’s been gone for about 2 weeks now *knock on wood*

Bosch 0242145518 / ZR5TPP33S ( I noticed are no longer in production?) They should be .8mm out of the box.

Coils are Delphi: 12138616153 / DEL-GN10571
The set came from fcp: 12138616153KT5

[twinscrolled]

DME failure would also be very rare and nothing you are experiencing would indicate a problem with the DME.

It could be a lot of things, but I doubt it's your plugs and coils. Corrections like these are typically fuel related at your build level.

But again, proper diagnosis is needed, random guessing won't help you.

[HeyTeeee]

But again, proper diagnosis is needed, random guessing won't help you.[/QUOTE]
Completely agree. I want to learn, makes everything easier down the road especially reading logs. Do octane boosters actually work? Every post I’ve read anyone who says yes is met with a swift no. OR gas has ~10% ethanol how much would yall say this plays a role?

[twinscrolled]

Some of them work and will bump the octane a full point or more, som are crap and will only bump it 0.1 of a point. The NOS octane booster is known to work, as well as Torco, Race Gas (brand), etc. They are probably not a good idea to run constantly but the do work. But again, you can just add some E85 as well. That will rule out a fuel quality issue.

[HeyTeeee]

Originally Posted by twinscrolled

Some of them work and will bump the octane a full point or more, som are crap and will only bump it 0.1 of a point. The NOS octane booster is known to work, as well as Torco, Race Gas (brand), etc. They are probably not a good idea to run constantly but the do work. But again, you can just add some E85 as well. That will rule out a fuel quality issue.

Unfortunately not the greatest log but does show some improvement. This is with some royal purple.

https://datazap.me/u/heyteeee91/log-1561833136?log=0&data=4-20-44-45-46-47-48-49