High idle, probably broken IAC, questions

[fixkick]

E17 market is Sweden ,sorry I forgot that. best is have signature in posts.
1991 Vitara MT, 2 door, G16a, 4wd. (market E17 Sweden, regardless of location this car is E17 no guessing)


there are 3 kinds of IAC (ISC in our case) in truth we only need 1 ISC not 2,(IAC+ISC) suzuki failed to do that and used 2.  (excuse is slow ECU then)

Ok.. Nice to know reason or excuse for doing such a hack. I have not seen similar "hack" in any old car I have had.
folks that race cars or go turbo or custom fuel injection do this all the time to all cars etc.  

I can confirm, no bleed screw found on mine. So for sure not USA CAR) So I guess tuning the duty cycle would be quite annoying.
yes no bleed = big pain. for sure. (jumping back and forth from TPS cal and dutycycle  i mad rush, then in USA 91, year all this pain ended. but not world wide.




I will drive next week to our summer place so I will leave the ISC as is for now.

Car works fine enough without it as I don't have AT creating extra drag trough torque converter so its very minor nuisance. what?
your  first post shows 1991 Vitara MT, 2 door, G16a, 4wd.

MT is not AT./ no mt has any kind of torque  converter,  I am so confused now.  and you are correct A/T box shifted Park to drive and NO ISC working will love to stall.


With luck I might find analog voltmeter from there.. everybody has stored all kinds of shit from 1920's to nowadays so might even find one.
the cheapest meter sold on earth is that, seen on all stores, even walmart here.  for $9 USD.



 If not I will try to figure out some meter when we return.


By the way, could one hack nowadays digital meters to measure average voltage from the control pulses if one puts rectifier + capacitor between the test terminal and power wire ?
that is  that stores peak voltage..


the problem with all digital meters is the maker does not tell what kind it really is.
so you know what sample and hold is?   it captures  the voltage on a cap in the meter the digitizes it. (using ACD)  and shows peak charge on the cap inside the meter.
others do ACD  direct and can read wrong, if it lands on a drop out. as a square wave will surly do.
there are single slow and dual slop ADC and DUAL do not lie ever. (it does 2 samples that must agree) and the removes noise from the signal. (we used to design them our our company)

other meters most costly have   a duty cycle mode, that works.

then AC mode a meter with RMS mode will read RMS of the square wave and that is wrong, so will any meter this is non RMS (cheap meters) that too is wrong

the problem is: It is not DC, nor is it a sign wave but is  square wave,.

VOM= in Volts DC only mode.
a needle meters has zero electronics inside, (DC) just resistor voltage dividers.   and the meter is just a coil (a 1/2 rotation DC motor is in the meter) pure copper and 1 magnet bar.
VOM im volts mode, are cave man simple and are very useful still,  for sure doing averages.


this allows it  to average, (true)
analog in this case means NO ADC, no digitizer.
and has just needle.


https://www.walmart.com/ip/Leviton-Range.../302081068

UK?


https://www.ebay.co.uk/sch/i.html?_from=...0&LH_BIN=1



all stores here, auto and walmart and hardware stores (home depot,etc) sell cheap $10 needle meter, VOM  imported from china.

nothing works better unless , scope or duty meter feature DMM.

sorry that I could not see your whole , TB< if had, I'd know it was outside USA. ( my bad I did not look up your firewall tag and see COUNTRY code there)
I  can the see all parts on any car any country up to 2004.  (data base here)



here is my duty meter,  and does work tried it.


https://fixkick.com/IDLE-AIR/dutycycle/9....html#2800


WAY #2 (not in any book)  i CALL the CAVE MAN WAY, THE LESS TOOLS THE BETTER? (no hammers or clubs, sure)


works only if IAC is good or blocked, and AUX air is used (your hack) and you are not the first to do that  here.
turn the TV, stop screw and get 800 RPM (must be normal hot engine)
then set the TPS (calibrate screws loose) so the idle switch is (has) just  closed. monitoring the TPS idle pin, 0v is closed, 5vdc means idle is DISABLED. 0v is good , just  barely into, 0v.

end.

the goal is the the ISC to wake up on a hot engine, and work and regulator RPM at 800. (cold rpm is your hack valve, by hand set)
good luck to you.....

the problem is if set wrong and the idle switch is late to open(0 to 5v transition) the ECu will fight your right foot, and bog/hesitate )

what I do is set the TPS switch using the feeler gauge first
https://fixkick.com/All-Pdfs/M89/TPS/89-...ation.html

what you can try is to set the TV to TV bore air gap like ours 91, to 0.001 or 0.0005" not fully closed but so closed it can NOT JAM (see that reason?) (your hack is the new air bleed, see? )
then set the idle switch to using 2.2mm feeler gauge.find the zero OHM to infinity transition point using the 2 loose TPS screws and C/D pins on TPS. (low ohms scale or 2k ohm scale seems best)
this will set the TPS correctly. for idle switch actions. ( the key factor is when your right foot moves down even a bit the ISC goes OFF LINE fast. (or it will fight you)
then ready to drive.
then to start the car add air using your hack cold start needs air so add it with HV hack valve.

and when hot engine or near, then you start to close your hack valve until 800 RPM is hit and drive.
on A/T car that is more tricky. for sure if wrong ECU in the car. (MT ecu in AT car?) but your car is MT well was when new.

cheers !