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E46 M3 (2001-2006) Engine: S54 - Max Hp: 333 hp at 7,900 rpm / 262 lb/ft at 4,900 rpm
Total Produced: 45,000+ - Years Produced: 2001 to 2006.

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Old Sat, Nov-09-2019, 04:41:38 PM   #1
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Default Cold Start enrichment RESOLVED!! (for me)

For the past year or more, Ive been trying to figure out how/why the threads on the forum were providing solutions for everyone but me. I followed their steps and adjusted scalars, and tables, and probably did things on my car parts wise, that werent needed.

Thats not to say I didnt build a good knowledge base. Diving into an area where I felt uncomfortable and lacked confidence, has given me the information I needed to make better informed decisions.

The people that dig through the files and figure this out, are amazing pools of knowledge!

Mods are in sig, but a short rundown of fuel related:
39lb injectors
Walbro 485 in-tank
Global fuel factor is still at the stock "1"
All previous tune changes were done to the alpha-N and fuel tables (to adjust for injectors)
AFD flex fuel piggyback system (controller unplugged during troubleshooting, 93OCT used)

That said, What completely fixed my cold start was the....get this....

The "Fuel Injection_WARM_UP ENGINE to COOLANT TEMP (8x8)" table. On the 2801 version, its located at hex address 0x814 ( I dont know where its located in any other XDF.).

So obvious, but I was hesitant to mess with it because in all my searching on this forum, I NEVER saw anyone mention it.

Its X axis is degrees Celsius and the Y axis is time in seconds. Z a fuel multiplier of sorts? Either way, I began to lower my z values until I was getting a much more manageable cold start AFR. in the stock file configuration, my AFR gauge would peg at 10, the lowest it shows. Now its sitting around 11.7 then rises MUCH faster as the car warms up.

Will it negatively impact my engine? I dont think so. Bore wash is very dangerous so leaning out the cold start should help my motor. Are there long term affects? Not sure yet. Maybe someone with more experience could chime in??

Was this table never mentioned because its a BIG NO-NO to adjust? Not sure.
Change the values at your own risk.

BIG shout out to Exodus454 for helping me understand the Alpha-N and its relation to the fuel tables. If it weren't for him I dont think I would have had the confidence to keep digging around and searching for this!

Since this is resolved, Ive been tweaking my alpha-N and fuel tables. The tune on the car had fuel trims all over the place!
Attached Images
File Type: png Stock_Warm_Up.PNG (16.6 KB, 28 views)
File Type: png Modified_Warm_Up.PNG (14.2 KB, 27 views)

ModeGrau Respray
Active Autowerke Gen3 Stage 2.5 C38-91-AA Headers-Supersprint-Meisterschaft-Vorsteiner-Brembo-AC Schnitzer-BBS-CSL
6MT swapped-RTD shifter-Amber Gang- Dual port Aquamist Advanced Fuel Dynamics E85 CMP Auto Engineering topside subframe reinforcement Redisn v2 plates

Last edited by Turb02; Sat, Nov-09-2019 at 04:45:24 PM.
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Discussing Cold Start enrichment RESOLVED!! (for me) in the E46 M3 (2001-2006) Forum - Engine: S54 - Max Hp: 333 hp at 7,900 rpm / 262 lb/ft at 4,900 rpm
Total Produced: 45,000+ - Years Produced: 2001 to 2006. at BMW M3 (E30 M3 | E36 M3 | E46 M3 | E92 M3 | F80/X)