hi there i have a 1989 rs turbo cvh efi, but when its started from cold for maybe the first minute it runs a bit spluttery, once warmed up no issue at all, does anyone no wot this could be? maybe the water temp sensor in inlet manifold? also noticed sometime when warm and you let foot offf the pedal, on decelaration you get a bit of backfiring.

 

Is the ignition timing adjustable ?, check this then check for any air leaks on the inlet side.
tabetha