[Gossypiboma]

Car is an 08' 335i 6MT w/ JB4 and DCI's, everything else is stock.

Some back story to begin with. On map 5 with simple 93 in the tank I constantly experienced timing drops on 1/2 3rd and 4th gear logs I would take. Decided to drop in 5g's of E85 and top off with 93. After letting the car adapt with 5+ 3rd gear pulls that car was amazing. No timing drops, smoothness through the entire rpm range unlike with plain 93.

I go to do a 4th gear pull and boom, half engine light and 29F2 code. I then set future use A to 2 and OL fueling to 75. Logged another pull in 3rd and it felt like crap and fuel trims were maxed over 50 the entire rpm range. I then started upping the OL fueling by 5 until I saw that fuel trims drop below 50 over the entire rpm band, this didn't happen until OL was at 95. I thought it was fixed so I did a 4th gear pull and 29F2 popped right back up.

Can I not run approx 30% E85? My fuel pressure never really dropped below 16 in any of my logs so my LPFP should be intact.

If I have to set OL fueling to 100 then it seems I am maxed at 30% e85 w/ 93. I don't see how that is reasonable since I have seen people run 50/50 without the back end flash.

Any ideas?

[Todd135i]

The problem is all cars are different and don't all respond well to high percentages of E85.

When I ran 40/60 E85/93, my trims would peak above 50 at times also. When Terry looked at them he never had me correct them.

Now, if you go by the instructions of the 29f2 code with JB4, you're actually supposed to reduce the number by 5 until it subsides. On a side note, if you're over 50 then you increase. So you're in that catch 22 circumstance.

Here are the exact instructions with a few things highlighted:

"*** NOTE *** In some cars the auto learning may not properly range open loop fueling, triggering false 29F2 fuel pressure codes, and you will need to set it manually. To do this first disable open loop learning by setting FutureUseA = 2. Then start with an open loop setting of 75. If you experience 29F2 codes lower the setting by 5 until they subside. If your fuel trims are stuck over 50, you experience run lean failsafe (2 SES flashes), or encounter frequent 2D25 tuner codes, increase the setting by 5 until they subside. If your high fuel pressure is consistently below 13 when open loop is 75% or higher you likely have a physical fuel pump problem. If you are unable to find a suitable setting to avoid both 29F2 and 2D25 codes you will need to reduce the alcohol content of your fuel (e.g. if mixing in E85 mix in less), lower the all map AFR settings to lean the air/fuel targets, or use a fixed boost map like 1 or 2."

If all else fails, send the log to Terry and see what he says. I have a feeling he'll point you right back to the 29F2 rules.

Good luck

[marv85]

+1 on above.

Although I find it weird that you are getting timing drops on map5. Reason for that is autotuning should go for les aggressive boost when it encounters timing drops... Hopefully E85 will help

[Gossypiboma]

Originally Posted by marv85

+1 on above.

Although I find it weird that you are getting timing drops on map5. Reason for that is autotuning should go for les aggressive boost when it encounters timing drops... Hopefully E85 will help

Which is why I put in E85, but at 30% it seems to be too much.

[marv85]

I run 50% ethanol no issues :P