Proper Procedure for Relieving Fuel Pressure - 90 Cadillac Deville

Greetings:

In order to diagnose/repair an issue with my sister’s 1990 Cadillac Deville, it is likely that I will need to relieve the fuel pressure (it is fuel injected). However, I have a question about how to properly do so.

In my 1996 Chevy Van (also fuel injected), I was able to relieve the fuel pressure properly by pulling the relay and attempting to start it. However, in the repair manual for the Cadillac (Chilton or Haynes, I cannot recall), it says one should remove the pressure by bleeding it, presumably at the Schrader valve. I am curious if pulling the relay would work on this vehicle, and if so why not? I am more comfortable with pulling the relay than bleeding the valve (I am afraid of making a mess or not relieving the pressure enough), so it would be preferable if I could take that approach.

Thanks.

If you let the vehicle sit for a half hour, the residual fuel pressure will bleed off so there is no fuel pressure.

Tester