‘91 coupe quattro cold start problems

[Christopher Gharibo]

My ‘91 CQ cranks fine but has difficulty starting when cold. Once it starts the subsequent cold starts and warm starts are fine. About eight hours later, cold starts are a problem again. 

I changed the 20 year old fuel pump and multi function temperature sensor without improvement. All the vacuum lines seem fine. I unplugged the coolant temp sensor behind the block without improvement. The fuel injectors are 034 and about 15 yrs old. 

The car runs and accelerates fine otherwise. 

Any other ideas would be greatly appreciated. 

CG