Thanks for the quick responses!

My pump runs continuously with the ignion on and engine NOT running and is
making a air mixed with liquid sucking kind of noise. In fact, more correctly,
it is pulsing on and off continuously.

If working properly, how does the pump know to run for only a spurt when  the
ignition is first turned on. Is there a pressure sensor that shuts off the
pump when the correct fuel pressure is reached OR is it a timed power spurt
controlled by a relay?

I suppose I'm either dealing with a fuel blockage, low fuel, faulty pump,  or
something more mysterious to me... faulty relay (?) loose or corroded
connection. Guess I'll have to run some tests.

The bus by the way starts fine and runs great for exactly 5 seconds. There
seems to be enough fuel in the tank (1/4 tank) but the bus has been sitting for
 6 mos. Ran fine when it was parked.

thanks for any insight.
Best,
Jeff
83.5 Westy
LA,CA