What is the norm for fuel pressure at the rail? 1992 f150 5.0. Been having the rough idle problem with a rich fuel smell. Runs a little better when cold but rough when warmer. But back to fuel pressure, turn key on and start I have 32 pounds, remove vacuum from FPR and goes to 40. Hook vacuum back up and rev up truck and goes no higher then 38. Turn truck off and in about 30 seconds and already down to 20. After 2 or 3 minutes its on 0. Could not find any fuel residue in the FPR so I wonder if fuel injectors are leaking. Thanks for any input.

 

I think your running pressures are normal. Your rough idle and the leakdown on shutoff do point towards leaky injectors.

 

Your fuel pressures are normal, the rough running after warmup suggests a lean condition, pull the plugs to see of they are pale tan or white. If so then pull codes and go from there, an exhaust leak upstream of the O2 can also cause this, or leaks/problems with the EGR or air injection systems.