engine rpm surge. help needed.

[fixkick]

we pinch all vacuum line first. for RPM drops.
not the FPR i'ts hand tested with my vacuum gauged hand pump (mityvac or clone) to find it leaking air.
a bad FPR also causes lean at higher throttle openings for sure WOT, because fuel pressure did not right , from the huge vacuum drop)
I always do FPR tests first the ECU can not work at all correctly with out of spec, fuel pressure, and is common on all these old cars.

just to let you know my car had both problems. at once. yah.

The ISC air line is on top I think. the cold hose of the 3 is AIR for sure. pinch it closed to take the ISC off line.
the TV is closed, and you checked it. (end this)
the IAC is blocked with say clay, or duct tape or someway, (yes i know its not easy to tape anything oily. be inventive here, there are no magic ways here sorry, )
the bleed screw is gently closed.
at this time no G16 on earth runs. ever. 0 air equals a dead engine.
if yes runs even at ~200 rpm , you have a massive air leak. gaskets or hose,
some leaks can be horror to find..

i had maf reading wrong
found the badguy left the induction man air pipe brace to the top of the exhuast manifold, and the pipe mount (pure aluminum) broke off the mount , making he engine run super lean.
got the car for pennies,
the found that horror in the back side of the pipe hiding very well,../ got new (used) pipe, car runs like new 97kmiles.