erratic idle
 

Hi
I have a 1990, 928 GT manual project which I have now got running again. However, when started from cold the car won't tickover, if you take your foot of the gas the car cuts out (tickover around 400-600 rpm), similarly it won't rev until warmer. When warm the tickover varies between 900-1100 rpm, the tickover is still erratic and sometimes cuts out, sometimes it won't rev straight away, you put your foot down and wait a second before the engine revs?
I have put a vacuum gauge on the front fuel damper vac line, when warm the vacuum is 15-17"hg. Anyone had similar problems?

where are you??
how old is the gas
what was the last thing you fixed