No announcement yet.

M50B25 non-vanos tuning options

  • Filter
  • Time
  • Show
Clear All
new posts

    M50B25 non-vanos tuning options

    I'm new to the E30 scene and purchased one with an m50b25 non-vanos engine swapped in. It is running rich as there is a smell of fuel and talked with the previous owner that it may be due to the Raceland headers that are put into it. He recommended I should look into finding a tunable ECU. I'm not finding any options for the m50b25 non-vanos motor. Any suggestions? Any alternative methods will help as well!

    Headers should make it run leaner, if any difference at all.

    Start with the fuel pressure regulator. When the diaphragm breaks, fuel gets sucked through the vacuum line, into the manifold.

    If that checks out, check the resistance on the blue coolant sensor. It goes to the ECU and if it's reading way too cold, the ECU will richen up the mixture.

    If that checks out, unplug the ECU for 5min and let it reset adaptations. If no change, then try unplugging ECU again, then unplugging the o2, reconnecting the ECU and not changes. If the car runs better, you have a bad o2 sensor or circuit - you can safely run without an o2 sensor, it will default to open loop.

    Check MAF & voltage. If MAF is reading wrong, the ECU will compensate wrongly.

    If all that checks out, overlook your injectors. Make sure they are the right part number. Lift the rail, turn the key to start and watch the injectors. Make sure none are squirting excessive, and that they are not dripping with engine off.
    Transaction feedback: Here, here and here. Thanks :D