I bought my SC about a month ago, knowing that it had a warm start issue. If it was within a few hours of me running it, I would try to start, and it would just crank and crank and never start. The only way I could get it started, was to pop the engine cover, and manually flip up the air dump valve. I suspected Fuel accumulator, given it only was an issue when warm. I'm still very new to 911's so my diagnosis skills are rudimentary. My mechanic tested the fuel pressures, and it was indeed not holding fuel pressure. I had the fuel accumulator replaced and now there is no issue with warm starts.
On warm starts, it fires immediately and it idles around 900.
The issue now is that on cold starts, regularly the car will crank for quite a while, and then splutter and start after 4-5 seconds. Seems like some cylinders fire, but it takes 30 seconds for the engine to be fully firing from what I can tell. Still have not had it never start, but nearly every time on cold starts now it takes a while to fire up, and it seems to be taking longer to fire over time.
In terms of what I should be doing, I assume buy a fuel pressure test kit, and test all 4 pressures as per
https://www.pelicanparts.com/911/technical_specs/Testing_Bosch_CIS.htm
Check fuel filter.
Anything else? Thanks in advance! Looking forward to getting my hands dirty in this.