Close

Page 1 of 2 12 LastLast
Results 1 to 25 of 47
  1. #1
    Join Date
    Dec 2012
    Posts
    300
    Rep Points
    373.9
    Mentioned
    6 Post(s)
    Rep Power
    4


    Yes Reputation No

    Misfires I haven't been able to solve for months...

    Original post form the "other forum" link if anyone wants to read the various pages


    Hating my car at the moment... Last night having some fun whipping around and get a SES light. Go home and check codes and this is what I get:Click here to enlarge


    The cat codes i'm not worried about since that's just the downpipes but the misfires are extremely annoying. Last summer I replaced cylinder 3 injector and then a few weeks ago cylinder 5. Spark plugs were replaced at 48k miles and i'm at 56k now so can't be that. Anyways so then I clear them and install ISO today. Go grab E85 and first pull I hear a loud pop like a backfire, flashing SES light and low power mode boosting 5 PSI for around 2 minutes. After that back to normal. Get home and pull the codes and get this:
    Click here to enlarge


    Idk what it is but as of now i'm just pretty annoyed. In my year of owning the car I don't think i've had it running 100% ever. I'm going to do a walnut blasting ASAP then after that see if the misfires are still occuring. If I get the multiple cylinder misfire after walnut blasting i'm just going to swap all coils and spark plugs since its relatively expensive. I just would really hate to have to replace more injectors since they are not cheap. Anyways just had to vent and let some anger out :mad0260:
    Basic updates is a few weekends ago I replaced plugs with NGK 5992's and misfires were still there. Went to Autocouture last Saturday to have walnut blasting done and misfires are still there... I have swapped coil packs and misfire didn't follow although they have been all over the place so i'm not ruling that out yet. Cylinder 3 injector was replaced last summer and then cylinder 5 injector a few weeks ago.

    If you go to the original thread you can see all the codes i've gotten since walnut blasting but it's basically been a mix of cylinder 4 and cylinder 5 misfires. I have no idea what it can be and what to replace next anymore but i'm trying not to just throw money at it guessing and replacing parts. If anyone has any ideas of what it might be let me know. I tried to attach some logs but couldn't get them to attach for some reason..

    Any help would be greatly appreciated
    Click here to enlarge < Click picture for photoshoot
    E90 335i xDrive 6spd, Nav, Prem, Cold Weather, & Sports package - Msport Conversion
    Mods: JB4 + MHD, Doc Race ST, Pure 6266, AD-Eng PI/Mounts, Fuel-It st. 3, Custom Exhaust, Tuned by TwistedTuning
    More Pictures: Build Thread /// Dyno Soon to Come

  2. #2
    Join Date
    Jan 2010
    Location
    SoCal
    Posts
    119,424
    Rep Points
    32,105.2
    Mentioned
    2106 Post(s)
    Rep Power
    322


    Yes Reputation No
    Please don't ask for help here and link there.

    That said, let's get you help.

    Stage 2 or 2.5 E9X M3 S65 V8 supercharger kit for sale
    : http://www.boostaddict.com/showthrea...r-kit-for-sale

  3. #3
    Join Date
    Mar 2012
    Posts
    330
    Rep Points
    353.4
    Mentioned
    10 Post(s)
    Rep Power
    4


    Yes Reputation No
    When do the misfires happen while driving? Low rpm? high rpm? Lugging the car? WOT top end?

  4. #4
    Join Date
    Dec 2012
    Posts
    300
    Rep Points
    373.9
    Mentioned
    6 Post(s)
    Rep Power
    4



    Yes Reputation No
    Click here to enlarge Originally Posted by Sticky Click here to enlarge
    Please don't ask for help here and link there.

    That said, let's get you help.
    I know only did it cause that has 8 pages worth of me replying to people with their questions so figured easier than answering again on here. I guess i'll just re-answer though. Definitely need help, it's getting to the point where i've contemplated parting out and trading for something else Click here to enlarge

    Edit: Oh yea btw congrats on 773whp! Very impressive and must be a ton of fun to drive

    Click here to enlarge Originally Posted by GeorgiaTech335Coupe Click here to enlarge
    When do the misfires happen while driving? Low rpm? high rpm? Lugging the car? WOT top end?
    In the way beginning like last month the misfires would mostly happen when ripping the car from a stop 1st-2nd. Now for the last month it has been under heavy load such as 4th gear 35MPH and hit full boost then it starts to misfire and throws codes. In map 2 it's much harder to get it to throw codes than Map 5 on E85 boosting 15 PSI+. Also on map 0 I haven't really felt any stumbling and haven't been able to get the car to misfire.

    On Saturday at Autocouture they originally thought it was my o2's and so did Terry since I have been occasionally getting that System check and Trimm control code. They guessed one of the backfires maybe burnt up an o2. They said while they were reading all 4 on the computer one was stuck at .1 while all the others were adjusting like normal. But then when they brought me out to show me they were all working normal. We then took it out for a ride and made the car misfire and didn't get the system check or trimm control codes so they changed their mind about it being o2's.

    Any ideas what to do next? A few suggestions i've had is clean the vanos with carb cleaner, swap all 6 coils to eliminate that as a possiblity, and then Autocouture's suggestion which they want me to do is make sure I have all new injectors (replace all but 3 and 5 since those were replaced recently). Only reason I don't think the injectors will solve it is i've been getting quite a few cylinder 5 misfires and that injector was just replaced a few weeks back and coded in. Really don't know what to do anymore and it's been stressing me out for weeks Click here to enlarge
    Click here to enlarge < Click picture for photoshoot
    E90 335i xDrive 6spd, Nav, Prem, Cold Weather, & Sports package - Msport Conversion
    Mods: JB4 + MHD, Doc Race ST, Pure 6266, AD-Eng PI/Mounts, Fuel-It st. 3, Custom Exhaust, Tuned by TwistedTuning
    More Pictures: Build Thread /// Dyno Soon to Come

  5. #5
    Join Date
    Mar 2012
    Posts
    330
    Rep Points
    353.4
    Mentioned
    10 Post(s)
    Rep Power
    4


    Yes Reputation No
    Click here to enlarge Originally Posted by psmith95 Click here to enlarge
    I know only did it cause that has 8 pages worth of me replying to people with their questions so figured easier than answering again on here. I guess i'll just re-answer though. Definitely need help, it's getting to the point where i've contemplated parting out and trading for something else Click here to enlarge

    Edit: Oh yea btw congrats on 773whp! Very impressive and must be a ton of fun to drive



    In the way beginning like last month the misfires would mostly happen when ripping the car from a stop 1st-2nd. Now for the last month it has been under heavy load such as 4th gear 35MPH and hit full boost then it starts to misfire and throws codes. In map 2 it's much harder to get it to throw codes than Map 5 on E85 boosting 15 PSI+. Also on map 0 I haven't really felt any stumbling and haven't been able to get the car to misfire.

    On Saturday at Autocouture they originally thought it was my o2's and so did Terry since I have been occasionally getting that System check and Trimm control code. They guessed one of the backfires maybe burnt up an o2. They said while they were reading all 4 on the computer one was stuck at .1 while all the others were adjusting like normal. But then when they brought me out to show me they were all working normal. We then took it out for a ride and made the car misfire and didn't get the system check or trimm control codes so they changed their mind about it being o2's.

    Any ideas what to do next? A few suggestions i've had is clean the vanos with carb cleaner, swap all 6 coils to eliminate that as a possiblity, and then Autocouture's suggestion which they want me to do is make sure I have all new injectors (replace all but 3 and 5 since those were replaced recently). Only reason I don't think the injectors will solve it is i've been getting quite a few cylinder 5 misfires and that injector was just replaced a few weeks back and coded in. Really don't know what to do anymore and it's been stressing me out for weeks Click here to enlarge
    The way you explain it would make me think injector(s). I have dealt with misfires probably more than most with stock turbos. I've had around 30 injectors on my car, almost as many coils, and 4 sets of plugs (60k miles). When my injectors would start to go, they would progressively get worse and become easier to induce a misfire. It started with only doing it on high boost in high gears lugging the engine, then eventually moved to lower boost and shorter gears. The misfire would usually occur right at full boost. When my coils went bad they usually would cause a misfire right after going WOT.

    PS - I've had to replace an injector weeks after replacing it previously. It is uncommon, but it can happen.

  6. #6
    Join Date
    Mar 2012
    Posts
    330
    Rep Points
    353.4
    Mentioned
    10 Post(s)
    Rep Power
    4


    Yes Reputation No
    Also, I've had times where the misfire would move to the weaker cylinder, one by one. I'd force a misfire, read the code, replace that injector, do another pull only to find a misfire in another cylinder that wasn't misfiring before. I'd then replace that one and it would either be completely fixed or would move again to another cylinder. It can be very frustrating, so I understand how you must feel.

  7. #7
    Join Date
    Nov 2009
    Location
    Simi Valley, CA
    Posts
    8,126
    Rep Points
    9,106.0
    Mentioned
    644 Post(s)
    Rep Power
    92


    Yes Reputation No
    If its always bank2 swap front and rear o2 sensors around to see if misfires move to bank1.
    Burger Motorsports
    Home of the Worlds fastest N20s, N54s, N55s, N63s, S55s, and S63s!

    It is the sole responsibility of the purchaser and installer of any BMS part to employ the correct installation techniques required to ensure the proper operation of BMS parts, and BMS disclaims any and all liability for any part failure due to improper installation or use. It is the sole responsibility of the customer to verify that the use of their vehicle and items purchased comply with federal, state and local regulations. BMS claims no legal federal, state or local certification concerning pollution controlled motor vehicles or mandated emissions requirements. BMS products labeled for use only in competition racing vehicles may only be used on competition racing vehicles operated exclusively on a closed course in conjunction with a sanctioned racing event, in accordance with all federal and state laws, and may never be operated on public roads/highways. Please see http://www.burgertuning.com/emissions_info.html for more information on legal requirements related to use of BMS parts.

  8. #8
    Join Date
    Jun 2012
    Location
    NJ
    Posts
    4,197
    Rep Points
    1,802.8
    Mentioned
    102 Post(s)
    Rep Power
    19


    Yes Reputation No
    Click here to enlarge Originally Posted by psmith95 Click here to enlarge
    Only reason I don't think the injectors will solve it is i've been getting quite a few cylinder 5 misfires and that injector was just replaced a few weeks back and coded in. Really don't know what to do anymore and it's been stressing me out for weeks Click here to enlarge
    Do you know whether you have the old or new (3rd revision) injectors installed?? I'm assuming you have the older ones because when you go to the newest (3rd) injectors, it requires replacing all 6. If you're 100% sure it's not the spark plugs or ignition coils (which it sounds like since you have new plugs & the misfires aren't following the coils), AND your intake valves have been cleaned up, it's more than likely you got a bad set of injectors. Depending on how recent and where you bought them, I'd try going back and getting those 2 injectors replaced/refunded under "warranty" (especially if you purchased from a dealer). Unfortunately, you're probably gonna be stuck buying a complete set of the new injectors.
    COBB AP ProTune by Bren of ///Bren Tuning
    Akrapovic DP | Helix FMIC | Alpina TCM Flash | Walbro 450LPH Fuel Pump


    "The moment money becomes your motivation, you are immediately not as good as someone who is motivated by passion and internal will." -A. Senna

  9. #9
    Join Date
    Apr 2010
    Location
    NYC
    Posts
    3,089
    Rep Points
    999.1
    Mentioned
    104 Post(s)
    Rep Power
    10


    Yes Reputation No
    Did you correctly gap those NGK plugs?

  10. #10
    Join Date
    Dec 2012
    Posts
    300
    Rep Points
    373.9
    Mentioned
    6 Post(s)
    Rep Power
    4



    Yes Reputation No
    Click here to enlarge Originally Posted by themyst Click here to enlarge
    Did you correctly gap those NGK plugs?
    Yes sir. Gapped them to .022 with this tool http://www.amazon.com/25025-26-Blade...+plug+gap+tool

    Click here to enlarge Originally Posted by benzy89 Click here to enlarge
    Do you know whether you have the old or new (3rd revision) injectors installed?? I'm assuming you have the older ones because when you go to the newest (3rd) injectors, it requires replacing all 6. If you're 100% sure it's not the spark plugs or ignition coils (which it sounds like since you have new plugs & the misfires aren't following the coils), AND your intake valves have been cleaned up, it's more than likely you got a bad set of injectors. Depending on how recent and where you bought them, I'd try going back and getting those 2 injectors replaced/refunded under "warranty" (especially if you purchased from a dealer). Unfortunately, you're probably gonna be stuck buying a complete set of the new injectors.
    I'm still on the 261 injectors. A few weeks ago when I first got a misfire cylinder 5 I assumed it was the same as last summer and an injector. I went on ebay and grabbed two 261 injectors, one for cylinder 5 and one as a spare just in case. I'm out of warranty so no way to have them swapped without paying and I really didn't want to pay $1200+ for 6 new injectors... Looks like that might be what I have to do. Autocouture wanted me to just find 3 more 261's for cylinder 1,2,4 then use my spare for 6 so i'd have 6 "new" 261 injectors. Problem with that is cylinder 5 is misfiring and that injector was a few weeks ago so maybe that one somehow went bad that quickly?

    Click here to enlarge Originally Posted by Terry@BMS Click here to enlarge
    If its always bank2 swap front and rear o2 sensors around to see if misfires move to bank1.
    It is always bank 2 except for that one time when I had a cylinder 1 misfire. That's actually a good idea but I feel like it will cost more than it's worth... Don't the downpipes need to be pulled to easily access all four? If so i'm xi so i'd be stuck paying for them to pull the downpipes then reinstall them if I find out it is o2's and have to get new ones put in.

    Click here to enlarge Originally Posted by GeorgiaTech335Coupe Click here to enlarge
    The way you explain it would make me think injector(s). I have dealt with misfires probably more than most with stock turbos. I've had around 30 injectors on my car, almost as many coils, and 4 sets of plugs (60k miles). When my injectors would start to go, they would progressively get worse and become easier to induce a misfire. It started with only doing it on high boost in high gears lugging the engine, then eventually moved to lower boost and shorter gears. The misfire would usually occur right at full boost. When my coils went bad they usually would cause a misfire right after going WOT.

    PS - I've had to replace an injector weeks after replacing it previously. It is uncommon, but it can happen.
    Click here to enlarge Originally Posted by GeorgiaTech335Coupe Click here to enlarge
    Also, I've had times where the misfire would move to the weaker cylinder, one by one. I'd force a misfire, read the code, replace that injector, do another pull only to find a misfire in another cylinder that wasn't misfiring before. I'd then replace that one and it would either be completely fixed or would move again to another cylinder. It can be very frustrating, so I understand how you must feel.
    Hmm that's interesting but I never would have thought the injector could have failed so quickly. Cylinder 5 was done literally less than a month ago
    Click here to enlarge < Click picture for photoshoot
    E90 335i xDrive 6spd, Nav, Prem, Cold Weather, & Sports package - Msport Conversion
    Mods: JB4 + MHD, Doc Race ST, Pure 6266, AD-Eng PI/Mounts, Fuel-It st. 3, Custom Exhaust, Tuned by TwistedTuning
    More Pictures: Build Thread /// Dyno Soon to Come

  11. #11
    Join Date
    Feb 2010
    Posts
    298
    Rep Points
    272.3
    Mentioned
    17 Post(s)
    Rep Power
    3


    Yes Reputation No
    I would say replace the O2 sensor on the bank with problems. Or even better, replace both of them, because the labor costs are high. Also log the low fuel pressure, etc. I remember someone having some misfire problems with the fuel pressure sensor and solved them by replacing it.

  12. #12
    Join Date
    Sep 2012
    Location
    Harrisburg
    Posts
    1,281
    Rep Points
    1,527.3
    Mentioned
    43 Post(s)
    Rep Power
    16


    Yes Reputation No
    I don't think you need to remove the DPs to get to remove the primary O2 sensors. I think what Terry is saying you should do is swap the two primary sensors and see if the problem moves to the other bank. Just remember to swap the end that plugs into the engine harness as well. You will probably have to route the cables over top of the engine to test this because the bank 2 sensor cable will not reach the bank 1 sensor plug on the engine harness.

    Swapping the primary and secondary sensors would not be advisable under any conditions. By "front" and "rear" I believe @Terry@BMS was referring to the bank 1 and bank 2 primary sensors only.
    Eppur si muove.

  13. #13
    Join Date
    Nov 2009
    Location
    Simi Valley, CA
    Posts
    8,126
    Rep Points
    9,106.0
    Mentioned
    644 Post(s)
    Rep Power
    92


    Yes Reputation No
    Sensor swap was presuming you're just doing the work yourself. Not practical to pay a mechanic to do it. In that case maybe start by replacing the rear sensors with new ones since you've thrown faults on them.
    Burger Motorsports
    Home of the Worlds fastest N20s, N54s, N55s, N63s, S55s, and S63s!

    It is the sole responsibility of the purchaser and installer of any BMS part to employ the correct installation techniques required to ensure the proper operation of BMS parts, and BMS disclaims any and all liability for any part failure due to improper installation or use. It is the sole responsibility of the customer to verify that the use of their vehicle and items purchased comply with federal, state and local regulations. BMS claims no legal federal, state or local certification concerning pollution controlled motor vehicles or mandated emissions requirements. BMS products labeled for use only in competition racing vehicles may only be used on competition racing vehicles operated exclusively on a closed course in conjunction with a sanctioned racing event, in accordance with all federal and state laws, and may never be operated on public roads/highways. Please see http://www.burgertuning.com/emissions_info.html for more information on legal requirements related to use of BMS parts.

  14. #14
    Join Date
    Apr 2011
    Posts
    216
    Rep Points
    331.7
    Mentioned
    8 Post(s)
    Rep Power
    4


    Yes Reputation No
    Did this happen after Down Pipe install? I switched the front O2's once and had similar problems. Took me 15 mins to swap to the right configuration and back in business.

  15. #15
    Join Date
    Dec 2012
    Posts
    300
    Rep Points
    373.9
    Mentioned
    6 Post(s)
    Rep Power
    4



    Yes Reputation No
    Click here to enlarge Originally Posted by NJrep335i Click here to enlarge
    Did this happen after Down Pipe install? I switched the front O2's once and had similar problems. Took me 15 mins to swap to the right configuration and back in business.
    Nope downpipes were installed a while ago last year

    Click here to enlarge Originally Posted by Terry@BMS Click here to enlarge
    Sensor swap was presuming you're just doing the work yourself. Not practical to pay a mechanic to do it. In that case maybe start by replacing the rear sensors with new ones since you've thrown faults on them.
    Don't trust myself to do stuff like drop the subframe to get access to the DP's for xi but i'll probably have them throw in the rear o2's next time i'm at the shop if at that time we still think that's it. When I get my USB cable today i'll go out and try to do some logs for you guys. One 3rd gear pull hopefully no misfires then i'll do my best to make the car misfire and log as it happens.

    Click here to enlarge Originally Posted by ajm8127 Click here to enlarge
    I don't think you need to remove the DPs to get to remove the primary O2 sensors. I think what Terry is saying you should do is swap the two primary sensors and see if the problem moves to the other bank. Just remember to swap the end that plugs into the engine harness as well. You will probably have to route the cables over top of the engine to test this because the bank 2 sensor cable will not reach the bank 1 sensor plug on the engine harness.

    Swapping the primary and secondary sensors would not be advisable under any conditions. By "front" and "rear" I believe @Terry@BMS was referring to the bank 1 and bank 2 primary sensors only.
    Maybe i'll try that but i'd still have to pay a shop to do it and sounds like a pain... I'm going to post up logs later today that will hopefully help to better pinpoint where the problem is

    Click here to enlarge Originally Posted by cstavaru Click here to enlarge
    I would say replace the O2 sensor on the bank with problems. Or even better, replace both of them, because the labor costs are high. Also log the low fuel pressure, etc. I remember someone having some misfire problems with the fuel pressure sensor and solved them by replacing it.
    Yea I have two rear o2's and the only codes i've got is for the rears. But don't the rears just do emissions whereas the fronts are AFR? If so then why would one rear being out make the car misfire?
    Click here to enlarge < Click picture for photoshoot
    E90 335i xDrive 6spd, Nav, Prem, Cold Weather, & Sports package - Msport Conversion
    Mods: JB4 + MHD, Doc Race ST, Pure 6266, AD-Eng PI/Mounts, Fuel-It st. 3, Custom Exhaust, Tuned by TwistedTuning
    More Pictures: Build Thread /// Dyno Soon to Come

  16. #16
    Join Date
    Dec 2012
    Posts
    300
    Rep Points
    373.9
    Mentioned
    6 Post(s)
    Rep Power
    4



    Yes Reputation No
    By the way just wanted to thank everyone so far for the help. Really do appreciate it
    Click here to enlarge < Click picture for photoshoot
    E90 335i xDrive 6spd, Nav, Prem, Cold Weather, & Sports package - Msport Conversion
    Mods: JB4 + MHD, Doc Race ST, Pure 6266, AD-Eng PI/Mounts, Fuel-It st. 3, Custom Exhaust, Tuned by TwistedTuning
    More Pictures: Build Thread /// Dyno Soon to Come

  17. #17
    Join Date
    Feb 2010
    Posts
    298
    Rep Points
    272.3
    Mentioned
    17 Post(s)
    Rep Power
    3


    Yes Reputation No
    Click here to enlarge Originally Posted by psmith95 Click here to enlarge
    Yea I have two rear o2's and the only codes i've got is for the rears. But don't the rears just do emissions whereas the fronts are AFR? If so then why would one rear being out make the car misfire?
    I thought it was obvious that the front O2 sensors are the important ones. You wasted your money for the rear sensors. Those don't have anything to do with misfires. I run without any rear O2 sensors (downpipes are plugged instead) and the car runs perfectly.

  18. #18
    Join Date
    Nov 2009
    Location
    Simi Valley, CA
    Posts
    8,126
    Rep Points
    9,106.0
    Mentioned
    644 Post(s)
    Rep Power
    92


    Yes Reputation No
    The rear sensors are used to calibrate the primary sensors...
    Burger Motorsports
    Home of the Worlds fastest N20s, N54s, N55s, N63s, S55s, and S63s!

    It is the sole responsibility of the purchaser and installer of any BMS part to employ the correct installation techniques required to ensure the proper operation of BMS parts, and BMS disclaims any and all liability for any part failure due to improper installation or use. It is the sole responsibility of the customer to verify that the use of their vehicle and items purchased comply with federal, state and local regulations. BMS claims no legal federal, state or local certification concerning pollution controlled motor vehicles or mandated emissions requirements. BMS products labeled for use only in competition racing vehicles may only be used on competition racing vehicles operated exclusively on a closed course in conjunction with a sanctioned racing event, in accordance with all federal and state laws, and may never be operated on public roads/highways. Please see http://www.burgertuning.com/emissions_info.html for more information on legal requirements related to use of BMS parts.

  19. #19
    Join Date
    Jan 2012
    Location
    NJ
    Posts
    972
    Rep Points
    1,406.3
    Mentioned
    31 Post(s)
    Rep Power
    15


    Yes Reputation No
    out of curiosity, are you running meth injection?

  20. #20
    Join Date
    Mar 2010
    Location
    Toronto, Canada
    Posts
    6,684
    Rep Points
    3,343.8
    Mentioned
    226 Post(s)
    Rep Power
    34


    Yes Reputation No
    Click here to enlarge Originally Posted by Terry@BMS Click here to enlarge
    The rear sensors are used to calibrate the primary sensors...
    huh? lol
    Click here to enlarge

  21. #21
    Join Date
    Sep 2012
    Location
    Harrisburg
    Posts
    1,281
    Rep Points
    1,527.3
    Mentioned
    43 Post(s)
    Rep Power
    16


    Yes Reputation No
    Click here to enlarge Originally Posted by Terry@BMS Click here to enlarge
    The rear sensors are used to calibrate the primary sensors...
    What information lead you to that conclusion. Just curious.
    Eppur si muove.

  22. #22
    Join Date
    Nov 2009
    Location
    Simi Valley, CA
    Posts
    8,126
    Rep Points
    9,106.0
    Mentioned
    644 Post(s)
    Rep Power
    92


    Yes Reputation No
    Click here to enlarge Originally Posted by dzenno@ProTUNING Freaks
    huh? lol
    Figured it out years ago when developing the dpfix. Throwing off the rear sensor signal a small amount eventually causes the primary sensor to go off track. Which causes all sorts of headaches as the DME thinks its running some AFR but is actually running richer or leaner than that. The system learns during sustained cruising where you're running close to stoich. Surprised you guys don't know about it. I guess you thought it was just magic adding an improperly calibrated dpfix to the rear sensor always causes primary sensor 2C31/2C32 trim codes? Click here to enlarge
    Last edited by Terry@BMS; 05-24-2013 at 11:48 AM.
    Burger Motorsports
    Home of the Worlds fastest N20s, N54s, N55s, N63s, S55s, and S63s!

    It is the sole responsibility of the purchaser and installer of any BMS part to employ the correct installation techniques required to ensure the proper operation of BMS parts, and BMS disclaims any and all liability for any part failure due to improper installation or use. It is the sole responsibility of the customer to verify that the use of their vehicle and items purchased comply with federal, state and local regulations. BMS claims no legal federal, state or local certification concerning pollution controlled motor vehicles or mandated emissions requirements. BMS products labeled for use only in competition racing vehicles may only be used on competition racing vehicles operated exclusively on a closed course in conjunction with a sanctioned racing event, in accordance with all federal and state laws, and may never be operated on public roads/highways. Please see http://www.burgertuning.com/emissions_info.html for more information on legal requirements related to use of BMS parts.

  23. #23
    Join Date
    Mar 2010
    Location
    Toronto, Canada
    Posts
    6,684
    Rep Points
    3,343.8
    Mentioned
    226 Post(s)
    Rep Power
    34


    Yes Reputation No
    That's interesting. Your dp fix does throw off AFRs and fuel trims making banks read differently from each other but I thought it was due to also touching the front o2 sensor signals not just rears.
    Click here to enlarge

  24. #24
    Join Date
    Sep 2012
    Location
    Harrisburg
    Posts
    1,281
    Rep Points
    1,527.3
    Mentioned
    43 Post(s)
    Rep Power
    16


    Yes Reputation No
    That makes sense because when you buy an aftermarket wide band sensor, you need to calibrate it periodically. Using the rear O2 signal when the engine is at or near stoich is a cleaver way to do that calibration automatically. I never realized this because I've never developed an oxygen sensor simulator.

    I installed a switch to enable and disable the DPFix, but I just interrupt the signal from the DPFix when the switch is set to "disabled". What I need to do is re-wire it so when disabled, it sends the rear O2 sensor signal to the DME, but when enabled it sends the DPFix signal to the DME.

    I would think it wouldn't matter if you have cats or not for the primary sensor calibration. The rear sensor just checks to make sure the post-catalyst exhaust gas makes rich/lean transitions less often than the pre-catalyst exhaust gas. If you don't have cats, the rear and front sensors will transition at the same rates, but if you are holding steady at 14.7 for calibration (or whatever the AFR happens to be), there are no transitions happening anyway.

    Sorry to go off topic, but it's an important point about the DPFix and it's effect on the engines air fuel ratio.
    Eppur si muove.

  25. #25
    Join Date
    Dec 2012
    Posts
    300
    Rep Points
    373.9
    Mentioned
    6 Post(s)
    Rep Power
    4



    Yes Reputation No
    Click here to enlarge Originally Posted by chrisisnapping Click here to enlarge
    out of curiosity, are you running meth injection?
    Nope although if I ever get this fixed I do plan on running meth eventually

    Click here to enlarge Originally Posted by cstavaru Click here to enlarge
    I thought it was obvious that the front O2 sensors are the important ones. You wasted your money for the rear sensors. Those don't have anything to do with misfires. I run without any rear O2 sensors (downpipes are plugged instead) and the car runs perfectly.
    It is obvious that the front o2's are the important ones. I bought the rear ones because I have had no codes for the front o2's, only the rear O2's. For "catalytic converter 2" in the rear i've gotten a system check and trimm control code although they have only appeared a few times and haven't showed up since.


    Anyways i'm going to head out in a few minutes to go do some logs. Went back to the G4 board until a replacement ISO comes because my G5 ISO wouldn't connect to the computer for some reason
    Click here to enlarge < Click picture for photoshoot
    E90 335i xDrive 6spd, Nav, Prem, Cold Weather, & Sports package - Msport Conversion
    Mods: JB4 + MHD, Doc Race ST, Pure 6266, AD-Eng PI/Mounts, Fuel-It st. 3, Custom Exhaust, Tuned by TwistedTuning
    More Pictures: Build Thread /// Dyno Soon to Come

Page 1 of 2 12 LastLast

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
  •