Car: '73 911S - stock

Getting my restoration project back on the road finally!!!

Engine starts ok when cold, and once warmed up, runs
very nicely without any mid-range surge. Idle is good,
and CO is at 3.5% at idle and 3-4% at 2500-3500 rpm,
so the rack seams to be adjusted correctly. Ignition
timing is also on correct.

When the car is warmed up, the engine will start if
you try immidiatly, but if you let it sit for more than
a minute, it will not re-start. The cold-start
injectors are not squirting (as they shouldn't) at
this point. I don't really know if I'm getting
too much or too little fuel at this point.
The car will re-start fine in about 2-3 hours.

I removed the injectors to soak them in Ventil Sauber
overnight, and when disconnecting the fuel lines from
the injectors, it seamed like the lines were dry (at
this point the car had sat for 4 hours). Is there some
sort of check valve in the MFI pump to keep the lines
filled, or is the pump expected to re-fill the lines
once you crank?

I'm not quite sure where to go from here, so if any one
had a similar problem, any thoughts or advice??

Thanks,

Gunnar