'93 960 sudden no start woes

My '93 960 abruptly ceased starting after I checked the fuel rail pressure
(50 psi btw). It had been running a little rich but there has been no
noticable impact on the drivability other than the persistent 231 and 512
engine codes. All that was done was connect a pressure gauge to the fuel
rail, turn the ignition on and off three or four times to bring it up to
full pressure, start the car, let it idle a few seconds to see if the
pressure changed, shut it off and disconnect the pressure gauge. The next
day it would only try to catch. I have tried it at least a dozen times,
sometimes for 15 seconds or longer but it only stutters and stumbles as long
as the starter is cranking. Any suggestions where to start looking for
problems? Thanks.

 

If your start while testing was from cold and it only ran for 1 minute or
less, at idle speed, and now it wont start, its almost guarenteed to be
flooded. Very common on the 5 and 6 cylinders when treated like this.

Leave it sit over night, then attack it with a wide open throttle and a long
burst of cranking until it is self sustaining then hold it at 3000rpm or so
til it runs smoothly, let it warm up properly before shutting off this time.

Tim..