idle surge is still here, tried everything possible. need help

[94talonawd]

ok. well today i went to get get a fiav block-off plate from qpr. well i installed it and my idle problem is still there. i dont know what is wrong anymore. ive searched every and tried almost all of the idle surge checklist.

ive tried alot of things.

heres a list of what i tried.
-new isc
-new coil pack
-new ignition control module
-new plugs and wires
-boost leak test, only had a little (the smallest leak you can imagine) leak coming from the upper ic piping
-blocked off the egr

-tried the fiav block off plate but didnt work.

well my vacuum is like at around 8. and my muffler sounds like its giving a misfire. the timing on my data logger jumps up and down. my injector d/c is always around 8. im guessing i have a vacuum leak somewhere? but where?

also, my echaust manifold is cracjked. could that be causing the poor idle?

what did u guys do to solve your idle problem? plz, i really need help. been trying o fix my idle problem for like 5 days straight now.