[techmaster05]

ill start off with a break down of what I have.
jb4 g5 iso
cxracing fmic
bms intake
m2 exhaust
bms catch can

I was at the track last night 1/4 mile and ran a 12.9@ 108 which is ok but I was having boost issues. I ran straight 100oct sunoco unleaded race gas with map 7 and less than half way down the track it switched to map 4. I afterwards ran strictly map 5 and it would not go over 15 psi which is not right considering all my mods and 100oct race gas.

I did not have any check engine lights come up but I scanned the dme and what do you know I got two stored codes.

2AAF. fuel pump plausibility
2A2D fuel low pressure system, fuel pressure.

I recently changed the valve covers due to an oil leak and my plugs and coils due to misfire codes which have been taken care of now.

I have noticed that when I start getting a little on it it sounds like the car tries to suck a lot of air in. and when I let go a lil it sounds like as if I had a really quiet bov. I dont believe I noticed this sound as much as before. I check the engine from up top but couldnt find anything loose.

I tries to do a search on the 2a2d code but dont seem to get much on it. only found one old post on it.

what do you think this might be??

[SteveAZ]

2aaf is very common on a tuned car. It's a shadow code that won't cause any issues but is simply telling you that your low pressure fuel pump is operating outside what the DME expects to see.

However, the 2a2d code may be due to you lpfp pressures dropping so you'll want to check the logs. The fact that you got kicked to map 4 may also be a sign of that if your hpfp pressures also dropped (possibly due to the lpfp drop) and your AFRs went lean.

Did you take any logs? We need to see those to get a better idea of what is going on.

As for the BOV sound...the BMS intake is going to contibute to that. Again, without seeing logs it's hard to tell for sure what's going on. It's probably fine since you aren't getting a 30ff code or anything of that nature.

[techmaster05]

I have never done a log but I do know how. whats a good speed zone to do it?? 0 to 60??? 60 to 100 ???

[SteveAZ]

Take it in 3rd gear from 2k rpms to redline at WOT. If you're an AT, make sure you don't hit the kick down and that your DTC is all the way off. You can post them here or send them to me at bmw.fuelkits@gmail.com

[techmaster05]

Originally Posted by SteveAZ

Take it in 3rd gear from 2k rpms to redline at WOT. If you're an AT, make sure you don't hit the kick down and that your DTC is all the way off. You can post them here or send them to me at bmw.fuelkits@gmail.com

im at so if I do 2k rpms it will most likely kick down to first

[SteveAZ]

BMS makes a kickdown blocker.....you're going to want that if you're going to be doing much logging and track time. You can go WOT without putting the pedal to the floor...you just want the software to see it's 100% but that usually doesn't require putting the pedal to the floor. Just takes a little practice

[techmaster05]

ok ill try from third once it gets a lil dry outside. ill just not floor it I guess. I didnt know they made something for the kick down but if I get the alpina flash ahoudnt that solve kick down

[SteveAZ]

No...I run the Alpina flash...that does nothing for the kick down. I'm not aware of any tune that defeats the kickdown switch.

[Bme30]

I had that code and it ended up being my low pressure fuel sensor. Since it has been replaced my car does not drop to map 4 and those codes are gone.
Run some logs and you will find your issue.

[techmaster05]

i got some logs for you guys. i had the jb4 phone app open yesterday at track so it actually saved some logs. the first two are from the track the last two are from today running map 5 on 93 oct pump gas. i couldnt get to much on it cause it was raining a little. it seems like i only got that code 2a2d while being on map 7. let me know what you guys think and if these are any good

from track last night






from today in rain. kept kicking back so no 3rd gear launches here

[SteveAZ]

Can you send me the CSV files?

You had some timing corrections and throttle closures when you were at the track on your first log. In the second log, things look better but I'm guessing that's map 5 and your boost targets were lowered.

On map 7 with the higher boost targets, you were using more fuel and your AFRs looked pretty good...so your fuel system was under a bit more strain.

[techmaster05]

sent you an email man, thank you for the help

[SteveAZ]

Okay....there is definitely an issue. This is probably one of the lowest LPFP readings I've seen, especially since you were running race gas and not E85.



So while your LPFP sensor is functioning, we have seen on occasion where a sensor will read low and replacing it resolved the issue. Yours was even low on straight 93 with moderate excelleration. The fact that your HPFP isn't completely taking a dive, makes me suspect the sensor although I wouldn't completely rule out the LPFP. The sensor is relatively inexpensive and fairly easy to change.

[techmaster05]

I guess thats where ill start. if thats not it should I replace the pump before the hp pump?