[s-cars] 93' S4 - Hard Starting

[Mock, Bruce J (Bruce)]

Hey Guys!  Looking for the groups collective wisdom here:
 
'93 S4 170,000 mi...exactly.
 
Car is hard to start - Sometimes - not all the time - hot engine or cold doesn't seem to matter - I have to crank and crank before she will run.  Other times she starts right up.  After a day and a half of this behavior, I did finally get a check engine light.  So... I went down to my favorite Denver area Mechanic/tuner, Champagne Motors, and had them pull codes.  Code for the Throttle. Pos. Sensor came up.  Hmmm.  We cleared that code with the hope that it would come back after a few motor starts, stops and driving.  It did not.  TPS code makes no sense to me since we know that you can disconnect the TPS and the car will start without it!  
 
My initial thought, based upon years of soaking up all of this great list wisdom was a bad Cam Position Sensor.  But doesn't a bad/flaky CPS usually set a code in the computer??  Also, the CPS is a bear to get to and is an expensive part - so hate to go blindly replacing this thing.
 
Champagne's thought was that this behavior might be due to a bad/intermittent fuel pump check valve.  But, this only makes sense if after a long rest (cold motor) e.g. - that you would need to crank for a long time to get fuel back into the system.  This AM, after a long cold night's rest, the car started right up!  That shoots the bad check valve theory, right?
 
At this point I'm at a loss...  So I'm just driving the car and living with the hard starts!
 
Interestingly, this all happened EXACTLY as the odo turned over to 170,zero,zero,zero miles.  Talk about planned obsolescence!
 
Bruce in Denver