Hot starting problems - MB

[quk@isham-research.demon.co.uk (Phil Payne)]

I've replaced the injector cooling fan thermoswitch.  The new one fixes a 
design issue - the old one had a male flat connector embedded directly in some 
sort of sealant, and the new one has a thick nylon cap cemented over it as 
addition support.  My old one was cracked, perhaps by someone working clumsily 
in the area, and I suspect moisture had got in.
 
I've not been able to do a 'hot' run yet, but on a quick trip to Tesco's I had 
the starting problem after a stand of 30 minutes.  I know the system pressure 
falls much too quickly when the pump is turned off and I'm now checking the non-
return (check) valve and the injectors.

One interesting question - the technical addendum that describes the Viton-
tipped injectors also says that they must be tested "within one hour of being 
removed from the car".  This implies that their characteristics change if 
they're not under pressure?  In contact with fuel?  Any ideas?

Is it possible that repeated overheating of the fuel lines/injectors has dried 
them out a number of times and damaged them? 

-- 
 Phil Payne
 Committee Member, UK Audi [ur-]quattro Owners Club