Porsche Repair: 1980 911SC Hot start problem, question thanks, fuel pressure

Question
QUESTION: My 911 runs sluggish on initial start, then problem disappears.  After running
until warm or hot the car will crank but won't start.  Once car cools down,
problem goes away.  I took it to local Porsche expert and each time he says it
is fixed?  They replaced check valve, fuel pump and found air boot blown off
- reinstalled and adjusted A/F plate.  Please let m know if there are some
simple trouble shooting I can do...instead of keep paying for bad diagnosis.

Thanks!

ANSWER: I would suggest asking the technician to look at it again since the issues was not resolved.

First I would look at is the no start after the engine is warm.  Maybe he can retest the fuel pressures: I would lean toward something like how is the fuel pressure bleeding down after the engine is turned off.  I'm assuming he replaced the check valve at the fuel pump however there is an accumulator (I thought) by the fuel filter (a bit more pricey to replace than the check valve).  

I had two different motors years ago that gave me hot start problems.
The first one had a bad coil; replaced the coil and the issue went away.  On the second motor is was vapor lock.

Resolve the hot start issue first, and then work on the sluggish cold running condition.

---------- FOLLOW-UP ----------

QUESTION: Thanks for info, what part causes a vapor lock and is there a way for to confirm
or resolve problem myself?  If the problem is with coil, I should be able to test
this by pulling a park plug and cranking engine when hot for spark, correct?

Answer
I'm leaning toward getting the car back to the shop that worked on it since you did pay for diagnostics in the repair and the repair is not completed.  

However, if you want to pursue this on your own you'll need more tools then what can be provided in a back and forth forum for a problem that can range from simple to time consuming.  

So here are some links to get you going:

BOOKS:
How to Tune and Modify Bosch Fuel Injection (Motorbooks Workshop) (Paperback)

Bosch Fuel Injection and Engine Management (Bosch) (Paperback)

DEDICATED SITES:
http://www.pelicanparts.com/911/technical_specs/Testing_Bosch_CIS.htm
http://www.pelicanparts.com/911/technical_specs/911_cis_troubleshoot.htm

DEDICATED FORUMS:
www.pelicanparts.com
www.rennlist.org