1973 911S MFI Starting Problems When Warm
 

The car starts fine when cold. When its warm depending on how long its been sitting - if for a few minutes starts immediately without having to prime the system. But when it sits longer and hour or longer and I don't get it to start on the first crank it almost takes forever to get it started sometimes practically draining the batter. What should I look for and check. What keeps the fuel in the system when warm or what primes it when starting it after a run and it's sitting for an hour or so.

I am based in the Philippines and our MFI specialist has migrated to Australia.

Hope someone can help.

Thank you.

Are you using the "Owner's Manual" starting procedure? Also, what do you mean by having to "prime" the system?
On my 73S with MFI when cold, I pull up in hand throttle and do not use gas pedal.
when hot, and sitting around 1 hour I put gas pedal to floor and crank.
when warm(been sitting over 1 hour to 2 hrs) I crank but at the same time pressing on the gas pedal and it usually starts as the pedal is about 1/2 to 3/4 to the floor. The warm start has always seems to take the most cranking.

Yes when cold I pull up the hand throttle. No problem at all when cold. When hot I step on the gas pedal a bit and it takes a while to start. You are right depress pedal 1/2 to 3/4 to the floor. The manual says fully depress pedal. WIll try that. Many thanks.

Also, hold key in on position( 5 to 10 seconds) and let electric fuel pump eliminate vapor lock. Then start.