Alarm! yes bypass.
http://www.clarks-garage.com/pdf-manual/elect-23.pdf
Then
Even though you changed the reference sensors and DME/fuel pump relay....
Did you try the DME relay '
jumper?
http://www.clarks-garage.com/pdf-manual/fuel-05.pdf
When you crank the engine with the key in the ignition..............
DO you get tach bounce---a little bump of 1/16th of an inch
When you look at the DME computer---do you see water damage?
Try tapping on the DME computer---wiggle the thick wire connector---carefully,
then start looking for a spare DME on ebay or parts wanted-----usually about $100 for the early 944.
Whether you need it or not, it is good to have a spare.
Here is the basic troubleshooting/no start info on Clarks Garage.
Troubleshooting - Engine
GL & welcome!
J_AZ