Hot start problems...

[evangelo@mecf.wustl.edu]

Hi Everyone,
I have significant problems starting my engine when its hot (say 10-20 cranks).
On the other hand when it's cold it will start either at once or after a couple
cranks. 
According to Bentley this can be from a number of causes, from fuel pump
to the air distributor. Unfortunately I don't have the time and even more the
equipment to run all the tests suggested.
So my question is, what is the most common mode of failure in my case ?

Thanks

Evangelos
'86 5000 CS Turbo (149K, with one spark plug cable down)

PS
I tried to open the air distributor (the black box with the squares on top, south of
 the fuel filter), but I don't think there is a way to reach the screw on the clamp
without dissasembling the fuel injection part. Is there a trick ?