welcome !!!!
"i cant do pinch test means, ?" (only that the pinches do nothing?, good !, that is a passing test if that is what you mean.) pinching a leaking hose, stops that leak. and idle goes normal (or air fuel mix does)
the 8v engine races idle fast for all vacuum leaks,
what does your engine do fully hot at 180F? water temp?
but your 16v is tad different MPI MAF based engine (no map sensor there!) your EFI runs of the MAF, totally for fueling rates.
the 16v can race too fast too,same thing cold, but when hot, the leaks do cause lean and slower rpm. (if uncorrected) keep in mind the 02 sensor tries to correct minor air leaks. (lean it goes , efi goes rich to correct it.) if the hot air leak gets too high the EFI can not correct that error. (for sure at low RPMs (idle)
EGR
id just bypass it, until the RPM issues are solved and you have lots of time to clean it or at least get the stall test to work, i bet it dont)
this old car with the older EGR (called the quad EGR ports,) the sidewidder "B" tube EGR pipe did not arrive until 1992 or 1993 and depends on which factory made your car, no matter, your car is quad EGR. very a hard to clean system....
back to air leaks, (there are 2 type, fresh air, or metered air, leaks) fresh if unmetered, and metered air is , like what the IAC+ISC +bleed air supply do.
there are many tests to find all vacuum (air) leaks, on any 16v.
Path 1:
the maf rear pipe, all the way to the engine head intake valves must not leak air (of any kind, not IAC+ISC+bleed caused){hot engine its only bleed + ISC}
takes lots of work to inspect that whole path..
on the 16v air leaks are tricky
cold engines, the fuel mix is rich , so air leaks cause faster idle. over normal fast idle. (1500rpm is typical cold idle, unless Canada or in alaska, can be more, via IAC ACTIONS)
as the engine heats the IAC starts closing, and RPM must drop, if not , something is wrong. big time wrong.
on a hot engine the fuel mix should be perfect, but any air leak will cause the mix to go lean and RPM drops, if said leak exceeds the control factors of ISC and oxygen loop live tuning.(closed loop its called)
if a leak is too large hot, then engine can slow down, go lean and have low engine power with gentle tip-in throttle.
there are many hoses to leak, and that main top huge air pipe must not leak (part 20 and 16 here?)
http://www.fixkick.com/fresh-air/92-95-suck1.JPG
the lower fuel injector cushions x4 ( ID #6 below) must not leak. (vacuum side of injector (mpi x4)
see the paths here.
![[Image: induction1a.jpg]](http://www.fixkick.com/fresh-air/Slide_Show/images/induction1a.jpg)
the TV #5 valve is first. it must be closed 99.9% at all times at idle, (up to 3 cables on the throttle all must be loose set to spec) the TV cable, 3sp A/T and cruise. cables.
the IAC is 100% closed on a hot engine, does yours get hot>? (170F +)?????? if not it will never close, and some just go bad.
the bleed screw needs to be set to 50% duty cycle so the ecu can control idle all the time. (can only be set when all leaks are cured, )
any place that leaks air (fresh air worse) is cause for problems. (both idle speed or lean air mixtures.)
EGR:
you defected the EGR VSV, that's ok, mostly but the top hose on top of TB to top of plenum box, needs to be plugged, too, EGR port that is . ported vacuum.
to fully defeat EGR. its just best to plug just that top hose. the EGR is dead now anyway, , no VSV and im sure the quad ports are clogged. (weekend lost to clean it)
Back to idle:
if all vacuum hoses prove to be leak free, id test the IAC.
if the IAC sticks open hot (or hot water pipes to it are clogged) the engine whil scream hot, does it? or is it too scary to run this engine hot (can be....)
my 97 this IAC failed.
that rectangular port is IAC main suction port (metered air input) I block this hole with clay, or "duct tape" and run engine ,not touching throttle!)
![[Image: 16v-MPI-Body1w.jpg]](http://www.fixkick.com/fresh-air/Slide_Show/images/16v-MPI-Body1w.jpg)
put the main pipe back, the MAF is not optional. put it all back as you found it, tight pipes and clamps.
i let it run and see the IAC body hit say 170f+ with my thermal gun and if the engine does not race hot now?, BINGO. IAC is bad. easy huh, just one simple test for IAC, (mostly, i test mine in pan of hot water)
then remove my clay, before any attempts at wild throttle activity.
warning removing the 16v IAC , the screws love to snap or strip. so I tend to do tests on car. using IR gun. (a pyro gun and clay tricks.)
vacuum leaks are hard to find, lots of possible paths.(just inspecting all hoses for cracks and the main air pipe and fittings for damage, is pretty easy,,, look and see.... works great.
lots of tests. some are dangerous. (liquid fuel spray tests tops that list of danger, I use propane gas )
on my 97, someone left the main huge induction clamps loose, and was allowed to bounce, the broke off the aluminum side tab and this tab left a huge hole in the side of that pipe, on the back side, hidden
looking matters. i had to weld it back with my TIG. some main input pip flex lines there, crack. this old. also and easy inspection point.
and same with those other large rubber hoses there, PCV pipe crack (there are 2)
and sure the ISC cleaning, it loves to get gummy when the EGR cloud hits the PCV cloud and makes GUNK.
![[Image: 3_02_11_15_11_54_33.jpeg]](http://www.fixkick.com/bbs2/Suzuki-bbs/gallery/3_02_11_15_11_54_33.jpeg)