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High idle, probably broken IAC, questions - Printable Version +- Car Repair Forum (https://fixkick.com/forum) +-- Forum: Suzuki (https://fixkick.com/forum/forum-suzuki) +--- Forum: Sidekick/Tracker (https://fixkick.com/forum/forum-sidekick-tracker) +--- Thread: High idle, probably broken IAC, questions (/thread-high-idle-probably-broken-iac-questions) |
RE: High idle, probably broken IAC, questions - fixkick - 07-06-2021 most of these OLD cars even 32 years old now.(89) the IAC is bad, the wax pellet inside goes bad and collapses and leaks air. ( the WHY) just like the wax pellet does in the thermostat in its housing coolant, at 10 years old. (for same aging reasons) The IAC lasts way longer , 20 years or so.... there is no easy cure, new TB are not sold now, only hacks possible.(or used dead TB from ebay even worse) or the air hose trick per poster. (simple for sure and effective) thanks for sharing, ! one could program and Arduino computer to modulate a new , generic IAC, but finding one is not easy , they are used in racing, but oops found one. Idle Air Control Valve for BMW 325e https://www.amazon.com/ROADFAR-Control-Porsche-Compatible-GT7610-730/dp/B0837PWVZQ/ref=sr_1_3?dchild=1&keywords=Idle+Air+Control+Valve+for+BMW+325e&qid=1625575435&sr=8-3 the problem is what are the coils inside, is this a solenoid like Suzuki or 2 way motor with 3 pins, I do not know. and must be known 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) 1: solenoid IAC (ISC) suzuki type now. 2: motor pairs as seen on EGR electric motor on 1996 J18 engines up. 3: stepper, as seen on my 88 jeep,4.0L I know of only 3 kinds. but I think the below is #2 (100 % self contained, , no TB needed at all or wanted) If I still had my 91' 8v and the IAC died, I'd be all over this, at midnight, oil time. ![]() RE: High idle, probably broken IAC, questions - jwunsch - 07-08-2021 (07-06-2021, 10:55 PM)fixkick Wrote: 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. I can confirm, no bleed screw found on mine. So I guess tuning the duty cycle would be quite annoying. 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. 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. 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 ? RE: High idle, probably broken IAC, questions - fixkick - 07-08-2021 (07-08-2021, 12:57 AM)jwunsch Wrote:(07-06-2021, 10:55 PM)fixkick Wrote: E17 market is Sweden ,sorry I forgot that. best is have signature in posts. RE: High idle, probably broken IAC, questions - fixkick - 07-08-2021 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) with the wrong meter, digital and diode and a cap. say 1UF 20Vdc. the diode converts AC to DC called rectification. the cap charges to peak. input voltage. unless it is huge uF and has a resistor added.(IDK), and then the voltage is less. to do laws called RTC time constants. T=RxC. (R = 0 = wire) so there is no answer. lacking cap value. but... a small cap used will charge to 14vc fast (alternator voltage) charging voltage. 13.3. volts is battery float voltage, not charging nor discharging (lead acid car battery) this is all useless, as we want to know actual duty, 50% high then 50% low on the square wave that is 2.5mS high , 2.5mS low. Period is 5mS. 0.005 seconds. it is so hard to do that suzuki sold there own meter to do that just for this car, the FSM factory manual even names it. the ISC has a 2amp driver , (6ohm coil ISC) this is very powerful signal and in to any meter , the meter is not going to load down that 2 pin wire set adding a diode to that pin is not any kind of resistance (T = RxC) R = 0. that means the cap (added to end of diode) adds no resistance and charges to peak. the DIODE then reverse bias (off) and the cap can not discharge to the low state driver or to the coil ISC, so sits at 14vdc all day long. do your really have Automatic trans-missing?????? or the MT 5 speed. the ECU for A/T box is unique. that A/T ECU actually sees you shift out of park and (park pin goes to false logic) the ECU changes to a very aggressive new idle controls to heat up (joking 1/2) the torque converter clutch. The magic ISC then holds 800rpm hot doing that,using totaly more aggressive ISC tables of modulation. if the iSC is dead the engine stalls or on very good engines runs a 200 rpm and does not. when you move the throttle with the right foot 1mm the ISC goes off line, dead ISC by design or the driver will crash (ask Toyota how billion $$$ law suit is to lose on that) My 91 has the ISC hunt error, a true man killer , in A/T (teens etc not wise) it hunts like mad if he DP fails. and no lawsuits yet. in drive it is a man killer (no me) for sure, in DRIVE, as car lurches madly ahead so do you have A/T tranny?????? RE: High idle, probably broken IAC, questions - fixkick - 07-08-2021 LAK625K17 let me decode that. L =metal top AK = 4 seats metal top 62 = 1.6L MT trans 5 speed. 5-= JLX grade. K= Type 1 engine 8valves. 17= for sweden export. market codes there was no automatic transmission in this car day one new. RE: High idle, probably broken IAC, questions - fixkick - 07-08-2021 IAC is in TB there were 2 TB , used, 2nd below after vin serial 000111445 13400-61a00 13400-61a60 never used in USA ever. but the IAC is deep inside, as you know. RE: High idle, probably broken IAC, questions - jwunsch - 07-08-2021 (07-08-2021, 03:17 AM)fixkick Wrote: Car works fine enough without it as I don't have AT creating extra drag trough torque converter so its very minor nuisance. what? Thanks again for that info package. I think I now understand how to correct the ISC issue. Mine did hunt before when semi warm until I hacked the IAC. It did not affect driving much. So yeah that confirms with A/T the hunting is really bad, probably due to the very aggressive ISC profile. And I dont pull from full stop with MT without pressing throttle pedal, so that also eliminates the ISC. Sorry for being bit confusing there. I mean to say that ISC not working is very minor minor problem as I have manual box. Also meant to tell that I know it would be huge problem with A/T as the engine would stall when switching to Drive. My country has only 5.5M population and spread across quite a lot of land. So we have limited selection of tools and stuff on shops. For example I have not seen analog voltmeter in 20+ years. Have to look up internet, someone on EU area must be selling those. I took a pick of my TB, sorry could not get to better angle with my camera. I marked one spot with red arrow that looks like it could have a screw, but there is only short cavity without screw. I know sports car tuners and race car guys have all kinds of exotic systems. I was helping my friend as a bolt/wrench boy role when he built his Mk4 Supra. From stock 330hp twin turbo to 1000+ hp single turbo ethanol monster... new ecu, new injectors, whole engine rebuild with stronger parts, 3 plate clutch, hardening gearbox, brakes, springs, shocks... so basically chassis and seats stayed as they were.. Self made ecu map and the works. Can just say that wow it was expensive and wow you really need the seat's backrest with that one. And maybe some driving skills. ![]() RE: High idle, probably broken IAC, questions - fixkick - 07-08-2021 (07-08-2021, 07:10 PM)jwunsch Wrote:(07-08-2021, 03:17 AM)fixkick Wrote: Car works fine enough without it as I don't have AT creating extra drag trough torque converter so its very minor nuisance. what? just be sure the TPS idle switch is closed at hot idle and driving will be so much better. (ok, still M/T) great. one other way (food for though) using and old VSV valve, vacuum solenoid valve, like what is used for the dash pot? use these with 12v( ign, on) power wire to and added VSV (vac, solenoid valve) and a toggle switch. then with the VSV and a tuned 1 orifice , . you have binary controlled bleed valve. for cold operation. or 3 way VSV for hot/cold and 2 orifices.. then tune the orifices one for hot and one for cold. set (tuned before) one way for cold and 1500 rpm as engine warms the 1500 goes way to high(too much air) "screams RPM at bout 150f water temp" then throw the toggle switch and 800 ISC regulated RPM happens. then latter you could add thermal switch device to water hose (a sensor) that closes (using a relay) to the above. toggle switch now removed. using sensor you choose as best, 150F or what ever you want ovoid the screaming RPM that you wish to avoid. note how this way is progressive from very simple to more complex but still easy to over time. (improvements) 3way (output to way 1 and way2 path) https://www.summitracing.com/parts/rnb-911-404 2way (open/ closed) (fo cold engine only) https://www.summitracing.com/parts/rnb-911-601 cheers had happy summer ! |