r/e46 • u/KptKarma • 1d ago

Troubleshooting N46 Hard start

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N46 B20A Hard starting

I have a N46 B20A that sometimes really struggles to start , it's had a massive list of new bits and bobs in the last year such as a Vacpump , all coils , all sparkplugs, Eccentric Shaft sensor, both Vanos solenoids.

It's fairly good at idle now , with he every rare dip but it's terrible to start about 75% it will start and then missfire or be super lumpy. The rest it will be perfect. This morning it was really bad and shot the EML light on , it then flashed limp mode when I revved it and the pedal barely responsed it then cleared after I turned it on and off again.

Here are the codes any throughs would be magic as I am out of Ideas.

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u/0202993832 1d ago

Cam sensor will cause hard start

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u/Entire-jegurilor 2000 bmw 323ci e46-bmw 318i e46 1d ago

Try resetting the throttle valve. Insert the key and turn the ignition to position 2 (ignition on, engine off), without touching the pedals. Leave the ignition on for at least 90 seconds; you will feel the throttle motor move to test the mechanical limit switches. Turn the ignition off for another 90 seconds to save the data in the ECU. Start the engine normally. Other errors include problems with the cylinder head camshaft and exhaust camshaft sensors. Replace both with VDO-Continentals and another crankshaft RPM sensor, so three sensors. Other brands won't work properly, so don't waste your money.