I installed and inline fuel pressure gage on the TBI supply line and noticed the pressure goes to zero as soon as the pump is shut off. Is this normal? From searching threads it sounds like the TBI should hold pressure for some time.

 

Yes, it's normal. Most fuel injected vehicles are supposed to hold fuel pressure for a while, but for some reason the TBI motors don't. As long as you've got 9-13 PSI for those first 2 seconds when the key is turned on or when the car is started and running, your fine.

I wondered about this myself a long time ago and got a similar response:
https://www.thirdgen.org/techbb2/sho...=fuel+pressure

 

thanks man...