Vintage Cars: fuel pressure issues on a 79 280ce mercedes, airflow sensor, sensor plate

Question
can a faulty warm up regulator cause the engine to run rich and not want to rev cleanly

Answer
if you mean a stumble or lag on acceleration then you need to check for sticking airflow sensor plate, sticking control plunger incorrect system or warm system pressure  or restricted injectors
WUR problems are typically cold and hot start issues and rough running