Paul,

The fuel pressure should remain in the system for 10 minutes after
shutting the engine off.

If you have high fuel pressure, the vacuum should be checked because a
low vacuum i.e. less than say 10", will produce higher fuel pressure,
which is exactly what the pressure regulator is supposed to do.

The vacuum source for the fuel pressure regulator should be beneath the
power brake booster. Verify that your vacuum hoses are connected
correctly, on Models with cruise control, the vacuum hose from the
cruise control vacuum pump, near right taillight, could be crossed.
Early models the distributor vacuum could be crossed. Verify your system
with Bentley page 24.24,a, b, or c schematic of the vacuum distribution
system.

Some models have the vacuum source for the fuel pressure regulator from
the Intake T-fitted to one nipple on the distributor, with the second
distributor nipple connected to the Throttle body. It's worth double
checking your systems because of the age and number of times this hoses
have been removed and refitted or replaced..

I believe you need to have at least 11" to the fuel pressure regulator
at the 880 rpm idle,
before you fault the fuel pressure regulator as being bad.

  Also the idle fuel pressure test value is 29 PSI at full vacuum and 36
Psi with no vacuum, above thirty-two with full vacuum would be cause for
suspicion.

Sincerely,

Mark Keller
91 Carat
Cowichan Bay, BC