[V8] 10 valve issues

[eric anderson]

I know it's totally unrelated to the V8 but i'll give it a shot.
My 88 10 valve 90 quattro runs sooo strong when it's warmed up.....but if it's dead cold it will crank for 10-15 maybe 20 seconds before it finally coughs to a rough idle and suffocates under any throttle.....this eventually evens out and like i said it runs fantastic hot or even mildly warm.
I have swapped out an entire fuel distributor...after that failed i changed - fuel pressure regulator.the entire fuel system has been replaced ie..all lines/accumulator/filter/pump seems fine though i have not checked fuel pressure because it runs so good warm......there are no vacuum  leaks since i refreshed the entire intake side while doing .....I have been in there sooo many times now i am ready to scrap this car....don't really want to but this is so un-nerving,,....any thoughts.....the V8 is running fine luckily it does not have the evil motronic or jet-tronic --whatever it is.
Thanks everybody for any input
Eric