i have posted a few times on this issue, so i hope im not irritating anyone!

i did a bunch of additional tests today all to no avail.

summary of problem: engine idles progressively higher as it warms up...after its warm, the idle races high, and then drops down for a second...over and over again...the problem began after a TB cleaning and replacement of several badly torn or missing vacuum hoses.

what ive done:
-rechecked all electrical connections
-disconnect throttle linkage to ensure TB is closed
-removed, tested, and cleaned IAC
-tested TPS signals at ECU
-replaced intake hose. actually found a crack in old one. didnt fix it :(
-tested temp sensor at ECU
-checked for codes, none present
-cut power to ECU to clear any adaptive history

during my ECU testing, the only thing that came back amiss, was the cold start valve test registered an open circuit. bentley claims i should see about 10 ohms resistance. is it possible this could be stuck open and dumping fuel in even after it warms up?

when i was at the pnp today, i also picked up a spare fuel pressure regulator. is this worth swapping out? has a bad FPR ever been known to cause a surging idle?

short of replacing the intake manifold gasket, which id prefer to avoid, i am running out of options?

thanks!