Well, I'm back to square 1 with my fuel pressure, '99 Accord EX, 2.3 VTEC - super stock. I measure 32psi regulated, and 38 un-regulated. Book calls for 38-46 reg, and 47-54 unreg. On previous post I had the pump removed, screen looked clean. Gumout'ed screen and that plastic canister that holds it all together, pressure went up some. Good thing there's no real fuel filter to blame...

Of course the P 0171/P0170 are up. Done some work under the car this weekend, the fuel lines look good as far as kinks/obturations that one can see.

This time I partially restricted the return line - engine running, I can see the pressure going up a lot, so the pump does the job. I suspect the pressure regulator, any other ideas?

 

That sounds like the fuel pressure regulator.