Mach 1,
I don't believe you should need to go below 33 psi. I know we've hashed this out over and over again, but the computer's limitation of fuel control isn't how little it can provide but how much it can provide. Your biggest concern should be how high the fuel pressure can go.
When you set your fuel pressure, it should be with the engine off and the fuel pump test connector grounded to force the fuel pump to stay on. Set it to 39 psi. Remove the ground on the fuel pump test lead and start the engine with the fuel pressure gauge still hooked up. Has the pressure dropped significantly? If not, there may be a vacuum leak in the FPR preventing the diaphragm from moving. If it does, hook up a vacuum gauge to a vacuum source as then move the throttle lever. Does the fuel pressure go up as the vacuum drops? If not, there may something wrong with the FPR.
If you confirm that the FPR is working properly, I would then look at sensors. 02, ACT, ECT, and MAF in that order.
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