just fitted a 2nd hand engine in my s1 that had done 12k. got car started but cuts out every time at idle, engine will keep running if i rev it, any ideas

 

Cold start valve possibly. If you keep it revving so it does'nt stall for a minute or so after starting, is it ok then ?

 

no car still cuts out after revving it for a minute

 

it could be a air leak check all the boost hoses and the breathers

my car had a problem like that it was the breather on the meter unit popped off the one coming from the rocker cover to the meter unit

have a good look