How to test the fuel pump / fuel regulator?

I beleive I have determined my loss of power to a low fuel pressure. The car used to idle at around 40psi, now it is around 32 psi and the car loses power after running for a while. I have also noticed that now the pressure bleeds down to about 10 psi within a few seconds of turning the car off. Does the fuel pump have a check valve to hold the pressure when it is turned off? Would that be a tell-tale sign of fuel pump failure? It also detonates (pings) at WOT. Is there anyway to test the fuel pump? Can I put my gauge on the fuel line where the fuel filter is? What should it read there before the regulator? I recently inspected the fuel regulator and it did not seem to be leaking fuel through the vacuum line although it is the original on a 95 with 115,000 miles. If I have to replace the regulator, what should I get, aftermarket or Ford? The fuel pump is also the original. I just don't want to pull the fuel pump unless I have to. If so, could someone point me at a good way to remove the gas tank? Do I really have to disassemble the exhaust to get to it? Is there anyway to access the top of the tank from inside the car? I have to replace the carpeting anyways so cuttting a hole and re-welding isn't really a problem. I guess i'm in denial again... SC denial.

The best way to check the fuel pressure is to rig up a gauge so you can watch it while you are driving and experience the problem.

If pressure is good at idle (check it with the vac line off) and then gets bad when under driving experiences, it could be a problem with the regulator or the pump.

There is a way to test the pump for flow by disconnecting a fuel line and jumpering the pump to run for a set period of time into a container that allows you to measure the amount that flows during that period. Someone can maybe post the details of how to do this if you want to pursue it.

The exhaust has to come off, and once off, the tank comes out pretty easy. You can cut into the floor under the passenger side of the rear seat and access the pump. I can't explain the specific area to cut but maybe someone else can.

I'd start with trying to monitor the fuel pressure while running down the road.

when was the last time you changed your fuel filter.. the system/pump has a relief valve ...in the event of restricted flow ...from .. fuel filter.. crushed fuel lines ..that will drop flow rate from pump .and yes also has check valve ...to hold system pressure.... after ignition has been turned off...dave

OK I rigged the pressure gauge so that i could watch it as I drive. The pressure seems low at idle (around 33psi) but when I punch it, the pressure steadily climbs to 50+psi at full boost. By the way, full boost on this car registers around 12-13 psi. I am unsure about the accuracy of the boost gauge. The vehical runs fairly well when cool except for a "studder" when you punch it. Once it "catches up" it pulls pretty hard. But once it gets warm (gauge at the R in warm) it begins surging and losing power substantially. All in all now, I feel like the fuel system is NOT the problem. I also disconnected the fuel filter and connected my gauge there. When I turn the key, each time the pressure increased 20 psi. By the third key turn, the gauge had 60+psi.
I pulled some codes yesterday. Came up with 241 pulsewidth error, 242 distributor ignition operating in failure mode and 538. I think the 538 error was due to insuficient RPM change during dynamic response test. So it seems to be pointing towards an ignition problem. I have new plugs and wires, installed a good coil from my 1993 SC, but I have not changed the cam sensor or the PCM. What do ya think?

Start with reseating all the connections on the EDIS module mounted on the passenger fender. If possible pickup some heat sink compound from an electronics store or radio shack and apply it to the bottom of the EDIS module.

Unbolt it from it's mount and check all the bolts for corrosion as well as what they bolt into. The EDIS grounds via the mounting bolts. Then clean off the bottom and apply the heat sink compound. Clear the computer codes and then give it a shot and see if things improve.

One of the biggest causes of loosing fuel pressure is this blow-off baffle Ford installed. The rubber eventally leaks and pressure bleeds off. Replace the fuel pump and install a rubber fuel hose in it's place.