[Jettin123]

I just purchased my 2007 335i on September 14th, it has 75K miles and the motor was all stock. I drove the car 11 hours back home and it did perfectly fine. On Sunday I added jb4 and dci, and the car was running good for about 30 miles, then started getting random misfires. I replaced the plugs with NGK 5922 this past Friday night and the car has been performing flawlessly on map 5.

This evening I decided to add five gallons of e85 and then top it off with 93 octane fuel. I drove for a few miles and did a couple third gear pulls so the jb4 could start to adapt with the new gas...by the third pull I did the car was crazy fast...boosting around 17/18 pounds. I drove for another few miles and was doing some spirited driving and everything was great, the car was very fast...but then I got a drop in power and was only boosting about 7/8 psi. Pulled over and turned the car off and then back on and everything was fine. Started getting on it again and it was good up until the top of third when the big check engine light came on on the lcd screen, once again only 7/8 psi. I cut the car off and then back on and it was all good, driving it mildly it would boost 15+ easy and have no problems, but as soon as WOT it will drop back down to 7/8 psi. One time it even had the SES light flash twice. Reading the jb4 start here thread: The JB4 has two active safety systems that will trigger SES light flashes. The first is the over-boost safety. If boost exceeds the value you've set under user adjustment the SES light will flash two times and the JB4 will switch itself to map 4 until you restart the car. The default setting is 18psi. Common causes for this are setting the value too low for the map/intended usage, improperly configured or defective wastegates, or JB4 setting problems.

I got home and logged the codes and I have 2AAF,2A87 and 3100.

What do I need to do to fix? Would I be okay with just adjusting the boost value? I am leaving for a big car show this weekend and want the car to perform flawlessly!

Thanks!

[buster84]

Originally Posted by Jettin123

I just purchased my 2007 335i on September 14th, it has 75K miles and the motor was all stock. I drove the car 11 hours back home and it did perfectly fine. On Sunday I added jb4 and dci, and the car was running good for about 30 miles, then started getting random misfires. I replaced the plugs with NGK 5922 this past Friday night and the car has been performing flawlessly on map 5.

This evening I decided to add five gallons of e85 and then top it off with 93 octane fuel. I drove for a few miles and did a couple third gear pulls so the jb4 could start to adapt with the new gas...by the third pull I did the car was crazy fast...boosting around 17/18 pounds. I drove for another few miles and was doing some spirited driving and everything was great, the car was very fast...but then I got a drop in power and was only boosting about 7/8 psi. Pulled over and turned the car off and then back on and everything was fine. Started getting on it again and it was good up until the top of third when the big check engine light came on on the lcd screen, once again only 7/8 psi. I cut the car off and then back on and it was all good, driving it mildly it would boost 15+ easy and have no problems, but as soon as WOT it will drop back down to 7/8 psi. One time it even had the SES light flash twice. Reading the jb4 start here thread: The JB4 has two active safety systems that will trigger SES light flashes. The first is the over-boost safety. If boost exceeds the value you've set under user adjustment the SES light will flash two times and the JB4 will switch itself to map 4 until you restart the car. The default setting is 18psi. Common causes for this are setting the value too low for the map/intended usage, improperly configured or defective wastegates, or JB4 setting problems.

I got home and logged the codes and I have 2AAF,2A87 and 3100.

What do I need to do to fix? Would I be okay with just adjusting the boost value? I am leaving for a big car show this weekend and want the car to perform flawlessly!

Thanks!

If you don't have a backend flash you cant go above 30% ethanol since the computer can only adjust for 33%. The reason your loosing power is that your maxing your fuel trims. 5 gallons of e85 is 33% ethanol. If your 91 (or 03) gas has more than 10% (which it can go upto 15% at the pump) that would mean that your running even more and the computer cant adapt.

Without a backend flash running anything more than 30% ethanol is a risk. Another issue you might be running into is a tired fuel pump. If your fuel pump is tired it could make e30 to much for your car, causing the jb4 to reduce timing and boost to compensate and get the fuel that its needed to run correctly.

If you run to much e85, the jb4 adapts the car (also the ecu) to reduce power and timing to allow you to get the correct lambda. Once the computer adapts you will be fine with that current mixture, but you will loose power. I'd suggest running down 1/4th a tank then filling back up. That should dilute the e85 enough to get your car back up to speed.

If you want to run more fuel, get the back end flash for the jb4, as well as an upgrade inline fuel pump or a walbro 455 e85 pump.

[SeanS54]

Originally Posted by Jettin123

I just purchased my 2007 335i on September 14th, it has 75K miles and the motor was all stock. I drove the car 11 hours back home and it did perfectly fine. On Sunday I added jb4 and dci, and the car was running good for about 30 miles, then started getting random misfires. I replaced the plugs with NGK 5922 this past Friday night and the car has been performing flawlessly on map 5.

This evening I decided to add five gallons of e85 and then top it off with 93 octane fuel. I drove for a few miles and did a couple third gear pulls so the jb4 could start to adapt with the new gas...by the third pull I did the car was crazy fast...boosting around 17/18 pounds. I drove for another few miles and was doing some spirited driving and everything was great, the car was very fast...but then I got a drop in power and was only boosting about 7/8 psi. Pulled over and turned the car off and then back on and everything was fine. Started getting on it again and it was good up until the top of third when the big check engine light came on on the lcd screen, once again only 7/8 psi. I cut the car off and then back on and it was all good, driving it mildly it would boost 15+ easy and have no problems, but as soon as WOT it will drop back down to 7/8 psi. One time it even had the SES light flash twice. Reading the jb4 start here thread: The JB4 has two active safety systems that will trigger SES light flashes. The first is the over-boost safety. If boost exceeds the value you've set under user adjustment the SES light will flash two times and the JB4 will switch itself to map 4 until you restart the car. The default setting is 18psi. Common causes for this are setting the value too low for the map/intended usage, improperly configured or defective wastegates, or JB4 setting problems.

I got home and logged the codes and I have 2AAF,2A87 and 3100.

What do I need to do to fix? Would I be okay with just adjusting the boost value? I am leaving for a big car show this weekend and want the car to perform flawlessly!

Thanks!

I run 5 gallons E85 with crappy Cali 91 octane on JB4 map 5 but I always switch to Map 1 first then back to Map 5. Drive it regularly for a few miles before getting on it. Works perfect for me.