5k cstq Rough acceleration at startup

[Kevin Boothroyd <kjb@blackmarket.mv.com>]

87 5000cs Turbo Quattro

I am experiencing rough acceleration during warm-up.
It has been getting worse over the past two weeks
and even more so after replacing the fuel pump a 
week ago. The idle is fine and runs good up to
about half throttle beyond that I seem to lose a 
cylinder. It only happens when the engine is 
completely cold. 

After-start and warm-up enrichment problem?
Leaking injectors or intake?