I just finished trying the same thing with the flashlight bulb with no luck. I hooked up a multimeter set on DC Volts instead of a flashlight and did see the needle move as juice was applied to the injectors. My 77 still won't start, but its been sitting since 93 so I guess it will be a little cranky. Oh well, on to the next step in the troubleshooting guide for me.
Both you and Texas280 need the Bosch " How to Tune and Modify Bosch Fuel Injection " manual. All of what each of you appears to be doing can be intelligently answered in this book. Perhaps your local library has it, or your local Z wrench will let you photocopy the pertinent page descriptions you each need to read. My 02. shane-
Thanks for the feedback. I have a copy the book you refer to. For those of you that might be on the lookout for it, it is has a good overall description of the different fuel injection systems Bosch manufactured, but does not have any more information than the FSM and certainly has no information on testing the ECU.