Bmw 320i stops when i plug in air mass sensor

Hello.

I have some problems with my bmw after engine swap.
I have swapped from M52B20 to M52B25.

The engine works good without the air mass sensor plugged in, but stops when i try to plug it in.

I have tried to change all sensors over from the old engine, but nothing helps.

I have also tried with three different air mass sensors, so i think this is ok.

Now i use the old ecu from my B20 engine, on the B25.
But i also have a M52B25 ecu without ews.

When i use the b20 ecu the engine works good, but with the b25 ecu i only could get it up to 3000rpm before it starts to missfire.

I wondering if it could be a ground fault somewhere, but i`m not sure.

Is there someone here who could help me with some tip maybe?

Sorry about my bad English but i hope something of it would be understanding





Kindly regard Tor Erik