Well a cuple of days ago gave me a 84 bmw 318i. at the time it wouldnt run, i determined the problem to be a bad in tank feul pump. so i replaced it and now the car runs but not for long.when i first start it it goes to about 2000 rpms stays ther for a bit then it starts to drop and then dies we ajusted the idle and that seems to be unresponsive at all. could this be a problem with the motronics ecu ro maybe somthing else . any input is apreciated.

thanks in advance derrek