Cold start/idle Issue!

[tquick79]

hot and cold engine both, you can even drive while its flashing. and it flashes 12, or errors.
this trick catches intermittent bad sensors.
does engine have full power driving on the road and up hills.?
does the tail pipe end smoke , black or white?
on old car like this G16a
Id first do basics, make sure the front crank bolt 17mm socket sizes is set to 94fl/lbs. , in 5th gear,brakes set hard. that saves damage to the crank cog up front. (i think you did)
then check compression 150psi x4 , wot, wide open throttle done or over 1/2 way throttle, so engine can suck air.
then check fuel pressure. at the filter, test port, banjo fitting 6mm threaded screw.
make sure the map hoses are not clogged end for end. the map must receive full vacuum at all times, from the intake plenum. or it will never run right.

do the clay test in on the IAC?
check all vacuum holes for leaks.? (the pinch test)
the TV stop screw , if you unscreew it hot engine, does the RPM drop to 800? if not the engine does have a vacuum leak, only where is the question. (lots of ways)

the are 3 ways to prove thermal IAC is bad hot engine, the 2 clay tests or the false base gasket. test.
pack this hole, and if hot idle is
http://www.fixkick.com/IDLE-AIR/Slide_Sh...r-n2bw.jpg

or pack this full. of clay. (or electrical mastic putty we call monkey poop , never gets hard this stuff)
see this 3 hole cavity, pack this in clay and IAC is dead. (Idle go 800 or less now?
http://www.fixkick.com/IDLE-AIR/Slide_Sh...-air2w.jpg

last the gasket trick


this one is super bad
http://www.fixkick.com/IDLE-AIR/Slide_Sh...ottom1.jpg

the 5 holes on the right must never be UN blocked by the gasket, the gasket must be solid there.
the H2o hole is blocked the IAC goes dead, stuck open forever.
the air hole is the IAC output, to the plenum. this can be blocked as test (custom gasket hand made) and if idle goes below 800 you found your leak (hot engine)

now keep in mind if you do block the IAC cold starts will want to flood so you must use right foot pressed say 5% to keep engine running and if when hot engine the idle is still high
there is a huge vacuum leak and is NOT the IAC.
we pinch hoses to find leaks or find cracked hoses the vacuum booster or is hose can leak air, and is more hard to block but can be done, but power brakes will be dead so dont drive.
the booster it self can leak.
the EGR base gasket can leak and suck air, there are many points in to this engine that can leak air causing vacuum leak and high idle even with TV stop screw CCW backed off.
ever clean the TV valve? it too can gunk up and not close.

the order i do this is by difficulty , all on a hot engine 180f+} water coolant temperatures.
1: Pinch hoses is so simple if idle drops bingo (do not pinch map hose, inspect ever inch and both nipples and make sure the far end sucks are when pulled off map.
pulling the map hose running will flood the engine so just know that. just make sure the map receives vacuum live.
2: close the TV valve, by turning the stop valve CCW and make sure it closes full,with
3: block the brake booster hose pipe with a cork. diskconnected (most easy way is that) large hose. idle ok now?
4: you can also block the ISC up top with fake solid gasket. idle ok now, below 1100 but goal is 800 or less hot, for sure less with ISC now dead.
5: clay block the IAC. this is the last normal idle air supply, once blocked NOW there is no air now.(cant run engine,.now unless fancy right foot actions(pressings)
6: once here the airless engine should stall due to lack of all air inducted. zero air and too much fuel if stalls.
7: bad gaskets under TBI body, or intake to head gasket 4 ports leaking, or loose intake manifold bolts.

I think i did all leaking paths for vacuum above. correct me if I missed any.
good luck to you.
but 1100 RPM hot is wrong. need to be found this leak.

Thanks so much for helping me with this! I’m off work a few days this week and will try all the above things you mentioned and let you know what I find. Thanks for the timely responses!