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Need Help with L-Jetronic M20B23

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    Need Help with L-Jetronic M20B23

    I have an '85 Euro 323i (Baur0 with L-Jetronic, The engine starts immediately when cold and idles smoothly..... however once the engine warms up and reaches operating temerature, the idle starts to t get irratic (rough) and eventually stall.Is there a warm-up regulator or similar component in L-jetronic FI that I should be checking.

    I've ruled out electrical (new wires, rotor and cap. Distributor dynamic timing has been set to 19' @ 5000 rpm. And I have checked vacuum pressure and done a smoke test to check for vacuum leaks.

    '85 323i Baur

    Done a compression or leak down test to confirm the engine is in good condition?

    The idle up control valve on the L-jet e30 is a coolant operated slide valve under the intake manifold.

    Do you have the 7th injector? If so it might be worth checking if that is working as it should. and try unplugging it when its running rough.

    L-Jet is an extremely primitive efi system and is VERY susceptable to vacuum leaks. even if you think you have fixed them all i would almost guarantee there is still one causing you issues. I stripped everything vacuum off my m20b23 and just controlled the idle using the throttle body. Worked well for years.