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Stock Problems/IssuesDiscussions related to warranty related issues and repairs, or other problems with the OEM parts and software for MINI Clubman (R55), Cooper and Cooper S(R56), and Cabrio (R57).
DashCommand or Torque apps with an OBD dongle can be used to monitor fuel rail pressure. Key on, engine off, you should see ~70 psi for fuel pressure. That tells you if the low pressure pump is working OK. Engine running at idle, should give you ~700-ish psi to verify the high pressure pump. Engine running under operation, you should see ~1700-ish psi. (If I remember correctly)
Thanks for that very helpful. Started this morning without any data logging. Car missed for 30-40 seconds then cleared up and started idling without issue.
Tonight we used both a EL327 dongle and a Foxwell 510 scanner. The EL327 would show us only the high pressure side. At the rail key on got 72.5 psi.
Flipped over to the Foxwell 510 code scanner. It will show and let us log both the low and high pressure. Started car no missing logged 987 to 1066psi at cold idle. The scanner logs the high pressure side in Megapascals
Thought I had saved the BMW codes to the Foxwell but now I can't locate them. Did save the OBDII codes from the EL327 and got the following of interest.
P0300 Raw code: 0300 ECU: Engine control unit Status: Confirmed OBDII: Random/multiple cylinder(s) - misfire detected Mini: Random/Multiple Cylinder Misfire Detected ============2============== P0301 Raw code: 0301 ECU: Engine control unit Status: Confirmed OBDII: Cylinder 1 - misfire detected Mini: Cylinder 1 Misfire Detected ============3============== P0303 Raw code: 0303 ECU: Engine control unit Status: Confirmed OBDII: Cylinder 3 - misfire detected Mini: Cylinder 3 Misfire Detected
Cleared all codes. Planning to hookup the Foxwell in the morning with a cold start log the high pressure side and see if we experience any missing and what the fuel pressure indicates while the symptom is present.
Last night after collecting dig information decided to put a few gallons of gas in it. Only 1.7 gallons remaining. Put four gallons in. Went out this morning, started fine without issue. Not willing to blame bad gas on the issue, would be strange. Will try again tomorrow morning to see if the symptom returns.
Misfires and cold start idle die condition had returned. Finally found a parameters within the scan tool. FP set point and FP rail pressure. At key on and start the car is commanding "set point" of 9 MPa (Megapascals). When the symptom was present it was clear the HPFP couldn't produce what the DME was commanding and observed at the rail pressure reading. Was able to get a good capture (below). Shared the data with the local Mini service department, with six months of the extended warranty on the HPFP left they replaced the unit.
0.61 is the key on pressure. Upon the first couple frames of the starter engagement, normal operation would expect to see a quick ramp to near 9.XX range. Occasionally during a long idle I recorded pressures falling into the 4's. Tell tale sign of the pump failing. Not conclusive but over the past several years I would get a code set and IC message "operating under reduced power". A key off/on or a clear codes would reset the condition for it to not appear again until months later. Guessing this may have been the early sign of the pump starting to degrade.
11-25-2020 | 06:26 PM
