No announcement yet.

C63, JB4, BMS Intake, E30mix -- Low Pressure Faults, Low Trims

  • Filter
  • Time
  • Show
Clear All
new posts

  • C63, JB4, BMS Intake, E30mix -- Low Pressure Faults, Low Trims

    Hi, I've been running the JB4 for a little over a month or so now. Ran maps 1-5 in that time, and was trying to dial in map5 with e30 fuel blend. Last Friday under WOT in 4th gear (map5), car cut out and went into limp mode. Got low pressure faults (P0087), emailed back and forth with BMS and we decided that map5 was best if used with race gas.

    Dropped down to map3 on the same tank of e30, all seemed 'better'. Had been doing logs and sending back and forth with BMS, one of the responses looked like fuel trims were are limp mode and set open fuel to 60--car had not powered down and given me a CEL at this point. Updated fuel loop to 60, reset adaptations and went to log again, felt somewhat better. Went to run another log and vehicle powered down into limp mode with the same P0087 fault.

    Id like to state I am in no way thinking this is the JB4 issue, just need to find out what's going on with my car. Has anyone else experienced this? Is my LPFP about to die on me? Under normal driving, all feels well. I'm still around half a tank, should I add 93 to dilute down to about e15, would this help solve anything?

    I've numbered the logs with 1, 2, 3&4. Any help would be much appreciated! The graph with the '1' in front is the latest graph, where the car cut out; one being the latest, 4 being the oldest.

    NOTE** would like to add that at this particular gas station, I've tested over 10 times within the last two years (I was e30 blend on my f80 for about 6 months before going full e85 for over a year). Its always testing around e90/e91.

    Attached Files
    Last edited by onoez; 10-12-2021, 06:20 AM.

  • #2
    BMS has responded to open fuel to 30 and lower the e85 mixture.

    Still curious as to if anyone has had issues with their LPFP or upgraded it?


    • #3
      Low pressure hasn't been a big issue but the high pressure pump is unable to keep up with demand especially on E85 mixtures. So if you encounter high pressure dropping then lower the E85 mix and/or boost.

      Setting open loop too high will also make fuel pressure related fault codes more likely.
      Burger Motorsports
      Home of the JB4 the worlds most popular turbocharged tuning system!

      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 click here for more information on legal requirements related to use of BMS parts.