BM3 flexfuel cold start issue

[F80_Jeff]

Running BM3 flex fuel kit with multimap stage 2 map 3 (93) tune. I noticed if I put more than around 60% ethanol in my tank my cold start is extremely rough and kicked a check engine misfire code a few times. Once the car is warm it runs fine. Other mods are downpipes, NGK one step colder plugs, BMC drop in filters, AA EL midpipe & crank hub fix. Any thoughts? Car starts fine on E60 or.less.

THANKS

[PandaxF82]

Double check your connections again from the flex fuel kit. Make sure everything is tight and nothing is pinching. Are you running most updated BM3 multimap file?

I'm running full E85 on the BM3 kit and have not encountered this. Are you running Catless downpipes? If you are, why do you still running cold start?

[F80_Jeff]

Originally Posted by PandaxF82

Double check your connections again from the flex fuel kit. Make sure everything is tight and nothing is pinching. Are you running most updated BM3 multimap file?

I'm running full E85 on the BM3 kit and have not encountered this. Are you running Catless downpipes? If you are, why do you still running cold start?

Yes I'm catless. I just never turned the cold start off. No other reason. I can try doing that but it still wouldn't explain why the issue doesn't exist with lower ethanol levels. I'll double check my connections tomorrow...and I believe I'm running the most recent file. I just re-download it two days ago. Is there a way to double check that?

Thanks

[PandaxF82]

Only other items that I'm running differently would be BMW flex fuel plugs that are made by NGK and I have ignition project coilpacks.

What is your HPFP setting on BM3? Is it set to original or OEM?

[F80_Jeff]

Originally Posted by PandaxF82

Only other items that I'm running differently would be BMW flex fuel plugs that are made by NGK and I have ignition project coilpacks.

What is your HPFP setting on BM3? Is it set to original or OEM?

I didn't adjust the HPFP its still on "choose" I'm assuming that defaults to OEM?

[ck_M3]

Do you by chance park your car outside?

On a previous car, I'd have terrible cold-start issues on e85 whenever I parked outside. It'd take a few cranks, and rough idling until the car was drivable.

I anticipate the same once I switch over for this platform.

[F80_Jeff]

Originally Posted by ck_M3

Do you by chance park your car outside?

On a previous car, I'd have terrible cold-start issues on e85 whenever I parked outside. It'd take a few cranks, and rough idling until the car was drivable.

I anticipate the same once I switch over for this platform.

No I have a garage and the car hasn't been below 50 degrees ambient since I added the flex fuel.

[PandaxF82]

Originally Posted by F80_Jeff

I didn't adjust the HPFP its still on "choose" I'm assuming that defaults to OEM?

Originally Posted by F80_Jeff

I didn't adjust the HPFP its still on "choose" I'm assuming that defaults to OEM?

Doesn't hurt to set to "Original". That's what I set mine to.

[MR RIZK]

I think there was a thread not long ago with a similar issue. The OP was blaming the tuner when the actual issue was the HPFP setting as per PandaxF82

[F80_Jeff]

Will do

[chewbakam4]

Originally Posted by PandaxF82

Double check your connections again from the flex fuel kit. Make sure everything is tight and nothing is pinching. Are you running most updated BM3 multimap file?

I'm running full E85 on the BM3 kit and have not encountered this. Are you running Catless downpipes? If you are, why do you still running cold start?

+1

[ckendri]

Originally Posted by F80_Jeff

Running BM3 flex fuel kit with multimap stage 2 map 3 (93) tune. I noticed if I put more than around 60% ethanol in my tank my cold start is extremely rough and kicked a check engine misfire code a few times. Once the car is warm it runs fine. Other mods are downpipes, NGK one step colder plugs, BMC drop in filters, AA EL midpipe & crank hub fix. Any thoughts? Car starts fine on E60 or.less.

THANKS

Interesting. I have almost the exact same issue. I have zero trouble with my custom E85 tune, but my BM3 flex tune set on 3 with over e60 will start and die. No CEL, but the car dies. Fires right back up, but can die 2-3 times sometimes. I'll check the OEM vs. choose because I set my custom E85 to OEM. Maybe that's the trick???

I am catless DP, NGK one step E plugs, BMC drop ins…

[hellokitty]

Originally Posted by ckendri

Interesting. I have almost the exact same issue. I have zero trouble with my custom E85 tune, but my BM3 flex tune set on 3 with over e60 will start and die. No CEL, but the car dies. Fires right back up, but can die 2-3 times sometimes. I'll check the OEM vs. choose because I set my custom E85 to OEM. Maybe that's the trick???

I am catless DP, NGK one step E plugs, BMC drop ins…

I've experienced the same thing everyone has mentioned. Try the following:

1) Set HPFP and Injectors to "Original" setting rather than OEM.

2) Disable cold start completely. This seems to cause a lot of trouble for many users. Just get rid of cold start. If you really want to keep cold start, set cold start RPM to the highest setting (1200 RPM). Issues occur when RPM drops below 1000 which can cause the car to die. The amount of fuel that BM3 can add to cold start appear to be limited by parameters outside of their control for whatever reason hence the rough idle. A custom tune can compensate for this, but it's not guaranteed to be perfect.

3) Set start up roar to Original or GTS setting if desired. This doesn't seem to make a difference in terms of idling issues.

4) Run NGK F8S (BMW flex fuel plugs). Gap them to 0.020.

5) Clean your MAF sensors using CRC maf cleaner.

[PandaxF82]

Why keep cold start on when you're on catless downpipes?

Also, typically I cycle 91octane at approx 5-6 fillups of E85. During that cycle I will usually pour 7-8oz of Red Line 60103-4PK Complete SI-1 Fuel System Cleaner.

Once that tank is empty and when I go back to E85, I run 1.5oz of Hotshots LX4 with my ethanol.

[F80_Jeff]

Originally Posted by hellokitty

I've experienced the same thing everyone has mentioned. Try the following:

1) Set HPFP and Injectors to "Original" setting rather than OEM.

2) Disable cold start completely. This seems to cause a lot of trouble for many users. Just get rid of cold start. If you really want to keep cold start, set cold start RPM to the highest setting (1200 RPM). Issues occur when RPM drops below 1000 which can cause the car to die. The amount of fuel that BM3 can add to cold start appear to be limited by parameters outside of their control for whatever reason hence the rough idle. A custom tune can compensate for this, but it's not guaranteed to be perfect.

3) Set start up roar to Original or GTS setting if desired. This doesn't seem to make a difference in terms of idling issues.

4) Run NGK F8S (BMW flex fuel plugs). Gap them to 0.020.

5) Clean your MAF sensors using CRC maf cleaner.

Thanks u will follow your suggestions and see what happens

[hellokitty]

Also, ethanol attracts moisture in the air and as a result, your tank could have water sitting at the bottom (alcohol is less dense than water so water will sink).

You may want to try something like this occasionally to get all of the water out of the fuel tank.

https://www.bgprod.com/catalog/gasol...-system-drier/

[hellokitty]

And this….

https://www.bgprod.com/catalog/gasol...stem-defender/

[F80_Jeff]

Thanks for all the suggestions. I'm running a full tank of 93 in the car right now and will report back after I go back to e85.

[F80_Jeff]

Happy to report that after running a tank of 93 and changing HPFP to "Original" & turning cold start off the issues I was experiencing seem to have been resolved. I currently have an E70 mixture in the car according to the flex fuel sensor and the car is starting up and idling smoothly. Thanks to everyone who helped with this.

[F80_Jeff]

Also would like to add that the power curve and overall character of the car now feels much smoother and refined. I can only assume this is the HPFP setting. Not sure exactly what original vs oem changes but there definitely seems to be a difference.

[stoes]

Originally Posted by F80_Jeff

Also would like to add that the power curve and overall character of the car now feels much smoother and refined. I can only assume this is the HPFP setting. Not sure exactly what original vs oem changes but there definitely seems to be a difference.

I had the same issue with the hpfp after I installed my bm3 flex fuel kit. I emailed ptf endlessly with no help, the fellow members here suggested I switch my setting from "choose" to original and it fixed it. I emailed ptf saying they should look into this and was basically told to mind my own business. This is 100% an issue and needs to be addressed. Glad you got it sorted out.

[F80_Jeff]

Originally Posted by stoes

I had the same issue with the hpfp after I installed my bm3 flex fuel kit. I emailed ptf endlessly with no help, the fellow members here suggested I switch my setting from "choose" to original and it fixed it. I emailed ptf saying they should look into this and was basically told to mind my own business. This is 100% an issue and needs to be addressed. Glad you got it sorted out.

Wow yeah this totally should be communicated to the community. Hopefully others will find their way here in the meantime as more of these kits go out into the wild. Since fixing the issue I'm extremely impressed with how smooth the multimap stage 2 is. Im currently running the map 3 (93) tune with full e85. It's a noticeable improvement over the regular stage 2 93 map.