Hello all.
 New member and just fitted an m42 in my e30 to replace the m40b18 that was in it. 
The guy I bought the engine of sent me the ecu/DME with the engine and is apparently posting up the correct one. However been nearly a week and no sign. 
From a Google search the m42 ends in 157.posted below is a picture of the current ecu from the m40. Can anyone confirm it it will work with the m42 as it has the same number. 
Thanks.